diff --git a/static/ui.js b/static/ui.js
index 4ddfebac..e6a5b8b2 100644
--- a/static/ui.js
+++ b/static/ui.js
@@ -3418,9 +3418,11 @@ function _addLiveModelsToSelect(provider, models, sel){
     const identity=optionIdentity(mid);
     if(hasExistingNorm(identity)){
       const sameGroup=Array.from(providerGroup.children||[]).find(o=>optionIdentity(o.value)===identity);
-      const incomingRoutable=String(mid).startsWith('@');
-      const existingRoutable=sameGroup&&String(sameGroup.value||'').startsWith('@');
-      if(!(sameGroup&&!existingRoutable&&incomingRoutable)) continue; // let proxy replace catalog twin
+      if(sameGroup){
+        const incomingRoutable=String(mid).startsWith('@');
+        const existingRoutable=String(sameGroup.value||'').startsWith('@');
+        if(!(!existingRoutable&&incomingRoutable)) continue; // let proxy replace catalog twin
+      }
     }
     const opt=document.createElement('option');
     opt.value=mid;
diff --git a/tests/test_issue5989_custom_proxy_picker_dedup.py b/tests/test_issue5989_custom_proxy_picker_dedup.py
index 8418933c..0b6a1550 100644
--- a/tests/test_issue5989_custom_proxy_picker_dedup.py
+++ b/tests/test_issue5989_custom_proxy_picker_dedup.py
@@ -87,6 +87,9 @@ const sameSuffix=makeSelect();
 addCatalog(sameSuffix,'vendor-a/deepseek-v4-pro');
 addCatalog(sameSuffix,'vendor-b/catalog/deepseek-v4-pro');
 sameSuffix.value='vendor-a/deepseek-v4-pro';
+const crossProviderLive=new Node('select');
+_addLiveModelsToSelect('custom:a',[{{id:'@custom:a:gpt-4o',label:'GPT-4o A'}}],crossProviderLive);
+_addLiveModelsToSelect('custom:b',[{{id:'@custom:b:gpt-4o',label:'GPT-4o B'}}],crossProviderLive);
 const unnamespaced=makeSelect();
 addCatalog(unnamespaced,'gpt-4o');
 _addLiveModelsToSelect('custom:llm-proxy',[{{id:'@custom:llm-proxy:gpt-4o',label:'GPT-4o'}}],unnamespaced);
@@ -95,6 +98,7 @@ console.log(JSON.stringify({{
   catalogFirst:snapshot(catalogFirst),
   selectedBare:snapshot(selectedBare),
   sameSuffix:snapshot(sameSuffix),
+  crossProviderLive:snapshot(crossProviderLive),
   unnamespaced:snapshot(unnamespaced),
 }}));
 """
@@ -132,6 +136,13 @@ def test_same_suffix_models_in_one_group_do_not_collapse():
     }
 
 
+def test_live_models_with_same_identity_survive_in_different_provider_groups():
+    assert _run_harness()["crossProviderLive"] == {
+        "groups": [["@custom:a:gpt-4o"], ["@custom:b:gpt-4o"]],
+        "selected": "@custom:a:gpt-4o",
+    }
+
+
 def test_unnamespaced_custom_proxy_value_deduplicates_with_catalog():
     assert _run_harness()["unnamespaced"] == {
         "groups": [["@custom:llm-proxy:gpt-4o"]],