diff --git a/src/app/api/dn-batches/[id]/assembly/route.test.ts b/src/app/api/dn-batches/[id]/assembly/route.test.ts
index ac8eb77..5dacf5d 100644
--- a/src/app/api/dn-batches/[id]/assembly/route.test.ts
+++ b/src/app/api/dn-batches/[id]/assembly/route.test.ts
@@ -147,6 +147,31 @@ describe("assembly revision route", () => {
   });
 });
 
+// Changing the grouping resets checks to one sources_current failure. That
+// must not silently delete the site's open question from the board.
+it("keeps an open site question when the operator saves a new grouping", async () => {
+  notesList.mockResolvedValue([
+    { id: "note-1", status: "candidate", pages: [1], checks: [
+      { id: "sources_current", passed: true },
+      { id: "site_decision", passed: false, detail: { question: "How long is each pipe?" } },
+    ] },
+  ]);
+  const response = await POST(request({ revision: 1, groups: [{ pages: [1, 2] }], dismissedPages: [], reason: "join pages" }), { params: Promise.resolve({ id }) });
+  expect(response.status).toBe(200);
+  expect(notesUpdate).toHaveBeenCalledWith("note-1", expect.objectContaining({
+    checks: [
+      expect.objectContaining({ id: "sources_current", passed: false }),
+      expect.objectContaining({ id: "site_decision", passed: false, detail: { question: "How long is each pipe?" } }),
+    ],
+  }));
+});
+
+it("leaves a note with no site question carrying only sources_current", async () => {
+  const response = await POST(request({ revision: 1, groups: [{ pages: [1, 2] }], dismissedPages: [], reason: "join pages" }), { params: Promise.resolve({ id }) });
+  expect(response.status).toBe(200);
+  expect(notesUpdate.mock.calls[0][1].checks).toEqual([expect.objectContaining({ id: "sources_current" })]);
+});
+
 it("clears old line-index and header overrides when different pages move into a candidate",async()=>{
  notesList.mockResolvedValue([{id:"note-1",status:"candidate",pages:[1],manual_overrides:{po_number_raw:"OLD",items:{0:"old-item"},item_edits:{0:{qty:99}}}}]);
  const response=await POST(request({revision:1,groups:[{pages:[2]},{pages:[1]}],dismissedPages:[],reason:"swap documents"}),{params:Promise.resolve({id})});
diff --git a/src/app/api/dn-batches/[id]/assembly/route.ts b/src/app/api/dn-batches/[id]/assembly/route.ts
index a2c29ea..566cd13 100644
--- a/src/app/api/dn-batches/[id]/assembly/route.ts
+++ b/src/app/api/dn-batches/[id]/assembly/route.ts
@@ -2,6 +2,7 @@ import { authorizeOperation } from "@/lib/auth/operation";
 import { NextResponse } from "next/server";
 import { pbAdmin } from "@/lib/pb";
 import { withBatchLease } from "@/lib/dn-pipeline/lock";
+import { siteDecisionChecks } from "@/lib/dn-pipeline/site-decision-model";
 import type { BatchMutation } from "@/lib/dn-pipeline/batch-mutations";
 
 export const dynamic = "force-dynamic";
@@ -57,7 +58,7 @@ export async function POST(
       return NextResponse.json({ error: "invalid_page_coverage" }, { status: 400 });
     }
 
-    const notes = await pb.collection("dn_batch_notes").getFullList({ filter: `batch = "${id}"`, sort: "note_index", fields: "id,note_index,status,stage,posted_at,line_posting,pages,page_from,page_to,assembly_revision" });
+    const notes = await pb.collection("dn_batch_notes").getFullList({ filter: `batch = "${id}"`, sort: "note_index", fields: "id,note_index,status,stage,posted_at,line_posting,pages,page_from,page_to,assembly_revision,checks" });
     notes.sort((a, b) => Number(a.note_index ?? 0) - Number(b.note_index ?? 0));
     const posted = notes.find((note) => note.status === "promoted" || note.stage === "posted" || Boolean(note.posted_at) || Boolean(note.line_posting));
     if (posted) return NextResponse.json({ error: "posted_candidate", note: posted.id }, { status: 409 });
@@ -110,7 +111,7 @@ export async function POST(
           status: "blocked",
           stage: "needs_review",
           reconciliation_preview: null,
-          checks: [{ id: "sources_current", passed: false, reason: "Page grouping changed. Re-run batch to rebuild this document from its saved pages." }],
+          checks: [{ id: "sources_current", passed: false, reason: "Page grouping changed. Re-run batch to rebuild this document from its saved pages." }, ...siteDecisionChecks(note.checks)],
         } });
       }
     }
diff --git a/src/lib/dn-pipeline/run-staged.ts b/src/lib/dn-pipeline/run-staged.ts
index aa976f6..840276e 100644
--- a/src/lib/dn-pipeline/run-staged.ts
+++ b/src/lib/dn-pipeline/run-staged.ts
@@ -6,7 +6,7 @@ import type { GroupingProposal } from "./grouping-review";
 import { createHash } from "node:crypto";
 import type PocketBase from "pocketbase";
 import { normalisePoNumber } from "../po-matching";
-import { openSiteDecision } from "./site-decision-model";
+import { openSiteDecision, siteDecisionChecks } from "./site-decision-model";
 import { documentIdentity, identityReferences, normaliseDocumentNumber, resolveNoteLines, runNoteChecks, type PendingDocumentIdentity } from "./checks";
 import type { PoItemRef } from "./match-po-item";
 import type { AliasRow } from "./aliases";
@@ -609,9 +609,7 @@ async function upsertCandidate(
   // A question an agent left for the site is a person's pending decision, not
   // something a page read can answer: carry it across the re-run and keep the
   // document blocked until the site replies.
-  const siteDecisions = Array.isArray(existing?.checks)
-    ? (existing.checks as CheckResult[]).filter((check) => check?.id === "site_decision")
-    : [];
+  const siteDecisions = siteDecisionChecks(existing?.checks);
   const waitingForSite = openSiteDecision(siteDecisions) !== null;
   const ready = isReady && !waitingForSite;
   const fields = {
@@ -854,7 +852,7 @@ async function markSurplusCandidatesForReview(
   await Promise.all(existing
     .filter((candidate) => !used.has(candidate.id) && !isTerminalCandidate(candidate) && !candidate.line_posting)
     .map(async (candidate) => {
-      await ownership.update("dn_batch_notes", candidate.id, { status: "blocked", stage: "needs_review", reconciliation_preview: null, checks: [{ id: "sources_current", passed: false, reason: "This document is outside the current page grouping. Review grouping and re-run batch." }] });
+      await ownership.update("dn_batch_notes", candidate.id, { status: "blocked", stage: "needs_review", reconciliation_preview: null, checks: [{ id: "sources_current", passed: false, reason: "This document is outside the current page grouping. Review grouping and re-run batch." }, ...siteDecisionChecks(candidate.checks)] });
     }));
 }
 
diff --git a/src/lib/dn-pipeline/site-decision-model.test.ts b/src/lib/dn-pipeline/site-decision-model.test.ts
index 529d0c6..94d157f 100644
--- a/src/lib/dn-pipeline/site-decision-model.test.ts
+++ b/src/lib/dn-pipeline/site-decision-model.test.ts
@@ -1,5 +1,34 @@
 import { describe, expect, it } from "vitest";
-import { lastAnsweredSiteDecision, openSiteDecision } from "./site-decision-model";
+import { lastAnsweredSiteDecision, openSiteDecision, siteDecisionChecks } from "./site-decision-model";
+
+describe("siteDecisionChecks", () => {
+  // Changing the page grouping rewrites a note's checks to a single
+  // sources_current failure. Without this the site's open question is wiped
+  // from the board and no one is asked any more.
+  it("keeps every site_decision check and drops everything else", () => {
+    const open = { id: "site_decision", passed: false, detail: { question: "How long is each pipe?" } };
+    const answered = { id: "site_decision", passed: true, detail: { answer: "6 m" } };
+    expect(siteDecisionChecks([
+      { id: "sources_current", passed: false, reason: "Page grouping changed." },
+      open,
+      { id: "po_resolved", passed: false, reason: "other" },
+      answered,
+    ])).toEqual([open, answered]);
+  });
+
+  it("returns an empty array for non-arrays and malformed entries", () => {
+    expect(siteDecisionChecks(undefined)).toEqual([]);
+    expect(siteDecisionChecks(null)).toEqual([]);
+    expect(siteDecisionChecks("nonsense")).toEqual([]);
+    expect(siteDecisionChecks({ id: "site_decision" })).toEqual([]);
+    expect(siteDecisionChecks([null, "text", 7, ["site_decision"]])).toEqual([]);
+  });
+
+  it("returns the original check objects, not copies, so detail survives", () => {
+    const check = { id: "site_decision", passed: false, detail: { question: "q", suggestions: ["a"] } };
+    expect(siteDecisionChecks([check])[0]).toBe(check);
+  });
+});
 
 describe("openSiteDecision", () => {
   it("reads the last unanswered question with its suggestions", () => {
diff --git a/src/lib/dn-pipeline/site-decision-model.ts b/src/lib/dn-pipeline/site-decision-model.ts
index a3476b3..242cec8 100644
--- a/src/lib/dn-pipeline/site-decision-model.ts
+++ b/src/lib/dn-pipeline/site-decision-model.ts
@@ -35,4 +35,18 @@ export function lastAnsweredSiteDecision(checks: unknown): AnsweredSiteDecision
   if (!answered) return null;
   const detail = detailOf(answered);
   return { question: text(detail.question) || text(answered.reason).replace(/^Answered:\s*/i, ''), answer: text(detail.answer), answeredAt: text(detail.answeredAt) };
+}
+
+/**
+ * Every site_decision check, ready to be spliced back onto a rewritten
+ * `checks` array.
+ *
+ * A question an agent left for the site is a person's pending decision, not
+ * pipeline output. Every producer that resets checks — a re-run, a page
+ * regrouping in the MCP tool, the same regrouping in the web UI — resets them
+ * to a single `sources_current` failure, which used to drop the question off
+ * the board with nothing left to ask it again.
+ */
+export function siteDecisionChecks(checks: unknown): Array<Record<string, unknown>> {
+  return checksOf(checks).filter(isSiteDecision);
 }
\ No newline at end of file
diff --git a/src/lib/purchasing/delivery-candidates.test.ts b/src/lib/purchasing/delivery-candidates.test.ts
index db84151..d8a4b28 100644
--- a/src/lib/purchasing/delivery-candidates.test.ts
+++ b/src/lib/purchasing/delivery-candidates.test.ts
@@ -22,3 +22,27 @@ it('retains surplus candidates when regrouping pages',async()=>{
  expect(result.status).toBe('committed');expect(store('dn_batch_notes').size).toBe(2);
  expect(store('dn_batch_notes').get('abcdefghijklmn3')?.status).toBe('dismissed');
 });
+// Changing the grouping resets the note to one sources_current failure. That
+// used to wipe the site's open question, so it silently vanished from the
+// board and nobody was asked (this happened live on ARS14 INV205).
+it('keeps an open site question when regrouping pages',async()=>{
+ const {pb,store}=memoryDatabase();const batchId='abcdefghijklmn1';
+ await pb.collection('dn_batches').create({id:batchId,assembly_revision:0,page_count:1});
+ await pb.collection('dn_batch_notes').create({id:'abcdefghijklmn2',batch:batchId,note_index:0,pages:[1],status:'candidate',
+  checks:[{id:'sources_current',passed:true},{id:'site_decision',passed:false,reason:'Pipe length unclear',detail:{question:'How long is each pipe?',suggestions:['6 m','12 m'],askedBy:'agent',askedAt:'2026-10-09T08:00:00.000Z'}}]});
+ await pb.collection('dn_batch_pages').create({id:'page00000000000',batch:batchId,global_page:1});
+ const ctx={pb,principal:{id:'agent',permissions:new Set<'read'|'write'>(['read','write'])}};
+ await mutateDeliveryCandidate(ctx,'set_delivery_grouping',{operationId:'83f33948-63c7-4a02-a45a-9ab18d3bdc02',batchId,revision:0,reason:'fix',groups:[{pages:[1]}],dismissedPages:[]});
+ const checks=store('dn_batch_notes').get('abcdefghijklmn2')?.checks as Array<Record<string,unknown>>;
+ expect(checks.map(c=>c.id)).toEqual(['sources_current','site_decision']);
+ expect(checks[1]).toMatchObject({passed:false,detail:{question:'How long is each pipe?',suggestions:['6 m','12 m']}});
+});
+it('does not invent a site question on a note that never had one',async()=>{
+ const {pb,store}=memoryDatabase();const batchId='abcdefghijklmn1';
+ await pb.collection('dn_batches').create({id:batchId,assembly_revision:0,page_count:1});
+ await pb.collection('dn_batch_notes').create({id:'abcdefghijklmn2',batch:batchId,note_index:0,pages:[1],status:'candidate',checks:[{id:'po_resolved',passed:true}]});
+ await pb.collection('dn_batch_pages').create({id:'page00000000000',batch:batchId,global_page:1});
+ const ctx={pb,principal:{id:'agent',permissions:new Set<'read'|'write'>(['read','write'])}};
+ await mutateDeliveryCandidate(ctx,'set_delivery_grouping',{operationId:'83f33948-63c7-4a02-a45a-9ab18d3bdc02',batchId,revision:0,reason:'fix',groups:[{pages:[1]}],dismissedPages:[]});
+ expect((store('dn_batch_notes').get('abcdefghijklmn2')?.checks as Array<Record<string,unknown>>).map(c=>c.id)).toEqual(['sources_current']);
+});
diff --git a/src/lib/purchasing/delivery-candidates.ts b/src/lib/purchasing/delivery-candidates.ts
index 290a079..d4fec8e 100644
--- a/src/lib/purchasing/delivery-candidates.ts
+++ b/src/lib/purchasing/delivery-candidates.ts
@@ -4,6 +4,7 @@ import type {PurchasingContext,OperationResult} from './types';
 import {MutationSchema,runOperation,operationRecordId} from './operations';
 import {RecordId} from './documents';
 import {PurchasingError} from './errors';
+import {siteDecisionChecks} from '@/lib/dn-pipeline/site-decision-model';
 const page=z.number().int().min(1).max(10000);
 const fieldSchema=z.object({doc_type:z.enum(['delivery_note','invoice','collection_note','unknown']).optional(),delivery_note_number:z.string().max(200).optional(),po_number_raw:z.string().max(200).optional(),supplier_name_raw:z.string().max(500).optional(),supplier_registration_raw:z.string().max(200).optional(),site_name_raw:z.string().max(500).optional(),customer_vat_no:z.string().max(200).optional(),date:z.string().max(100).optional(),received_by_name:z.string().max(200).optional(),skip_customer_identity:z.boolean().optional()}).strict();
 const itemEdit=z.object({lineIndex:z.number().int().min(0).max(199),description:z.string().max(2000).optional(),qty:z.number().finite().min(0).nullable().optional(),unit:z.string().max(100).optional(),product_code:z.string().max(200).optional()}).strict();
@@ -52,7 +53,7 @@ export async function mutateDeliveryCandidate(ctx:PurchasingContext,action:'crea
   const ids:string[]=[];
   for(const [index,group] of grouping.groups.entries()){
    const note=active[index],id=note?.id??hash('sha256',`${root}:candidate:${index}`).slice(0,15);ids.push(id);
-   const data={pages:group.pages,page_from:Math.min(...group.pages),page_to:Math.max(...group.pages),assembly_revision:nextRevision,manual_overrides:{},status:'blocked',stage:'needs_review',reconciliation_preview:null,checks:[{id:'sources_current',passed:false,reason:'Page grouping changed. Process this batch again.'}]};
+   const data={pages:group.pages,page_from:Math.min(...group.pages),page_to:Math.max(...group.pages),assembly_revision:nextRevision,manual_overrides:{},status:'blocked',stage:'needs_review',reconciliation_preview:null,checks:[{id:'sources_current',passed:false,reason:'Page grouping changed. Process this batch again.'},...siteDecisionChecks(note?.checks)]};
    if(note)await lease.update('dn_batch_notes',id,data);else await lease.create('dn_batch_notes',{id,batch:batchId,note_index:index,candidate_key:`mcp:${id}`,doc_type:'unknown',items:[],...data});
   }
   for(const stale of active.slice(grouping.groups.length))await lease.update('dn_batch_notes',stale.id,{status:'dismissed',stage:'dismissed',reconciliation_preview:null,checks:[{id:'grouping_superseded',passed:false,reason:'Retained previous candidate after page grouping changed.'}]});