diff --git a/static/sessions.js b/static/sessions.js
index f2543e3a..bde3a1c4 100644
--- a/static/sessions.js
+++ b/static/sessions.js
@@ -4439,12 +4439,20 @@ async function _runRenderSessionListRefresh(opts, _gen){
   try{
     if(!($('sessionSearch').value||'').trim()) _contentSearchResults = [];
     const sessionListQS = _sessionListQueryString();
-    const sessionRequestOpts={timeoutToast:false};
+    // #5394: the sidebar session-list GET is idempotent, so 502/503/504 retry
+    // must be unconditional. Previously retries/retryStatuses were boot-gated, so
+    // a transient 502 during an nginx->backend restart on a warm refresh (profile
+    // switch, focus/visible/reconnect) failed on the first attempt and left the
+    // sidebar stale until a hard reload. Boot still keeps the larger timeout +
+    // timeout retry; every refresh now retries the transient upstream statuses.
+    const sessionRequestOpts={
+      timeoutToast:false,
+      retries:1,
+      retryStatuses:[502,503,504],
+    };
     if(!_sessionListHasLoadedOnce){
       sessionRequestOpts.timeoutMs=_SESSION_LIST_BOOT_TIMEOUT_MS;
-      sessionRequestOpts.retries=1;
       sessionRequestOpts.retryTimeouts=true;
-      sessionRequestOpts.retryStatuses=[502,503,504];
     }
     const {sessData, projData}=await _loadSidebarSessionListPayload(sessionListQS, sessionRequestOpts);
     // Discard stale response — a newer renderSessionList() call superseded us.
diff --git a/tests/test_performance_polling_hardening.py b/tests/test_performance_polling_hardening.py
index 23f072d9..61851288 100644
--- a/tests/test_performance_polling_hardening.py
+++ b/tests/test_performance_polling_hardening.py
@@ -24,7 +24,7 @@ def test_session_list_refreshes_are_coalesced_while_in_flight():
     assert "_renderSessionListQueuedRequest={" in src
     assert "opts:_mergeRenderSessionListOptions" in src
     assert "if (_gen !== _renderSessionListGen) return" in src
-    assert "const sessionRequestOpts={timeoutToast:false};" in src
+    assert "const sessionRequestOpts={" in src
     assert "api('/api/sessions' + sessionListQS,sessionRequestOpts)" in src
     assert "api('/api/projects' + projectQS,{timeoutToast:false})" in src
 
diff --git a/tests/test_session_sidebar_resilience.py b/tests/test_session_sidebar_resilience.py
index f80d528e..7c4caa62 100644
--- a/tests/test_session_sidebar_resilience.py
+++ b/tests/test_session_sidebar_resilience.py
@@ -56,22 +56,44 @@ def test_sessions_and_projects_load_independently_so_projects_failure_cannot_bla
     assert "_applySessionListPayload(sessData,projData)" in block
 
 
-def test_sessions_api_uses_longer_timeout_and_timeout_retry_for_boot_refresh_only():
+def test_sessions_api_always_retries_transient_upstream_statuses_and_boot_keeps_longer_timeout():
+    # #5394: the sidebar session-list GET is idempotent, so retries + retryStatuses
+    # (502/503/504) must be set on EVERY refresh — not gated to cold boot — so a
+    # transient 502 during an nginx->backend restart on a warm refresh (profile
+    # switch, focus/visible/reconnect) is retried instead of leaving the sidebar
+    # stale. The larger boot timeout + timeout retry stay boot-only.
     sessions_src = _sessions_js()
     workspace_src = _workspace_js()
+    refresh_start = sessions_src.find("async function _runRenderSessionListRefresh")
+    assert refresh_start > 0
+    refresh_end = sessions_src.find("async function _loadSidebarSessionListPayload", refresh_start)
+    assert refresh_end > refresh_start
+    refresh = sessions_src[refresh_start:refresh_end]
     helper_start = sessions_src.find("async function _loadSidebarSessionListPayload")
     assert helper_start > 0
     helper_end = sessions_src.find("async function _drainRenderSessionListQueue", helper_start)
     assert helper_end > helper_start
     helper = sessions_src[helper_start:helper_end]
 
-    assert "const sessionRequestOpts={timeoutToast:false};" in sessions_src
-    assert "if(!_sessionListHasLoadedOnce){" in sessions_src
-    assert "sessionRequestOpts.timeoutMs=_SESSION_LIST_BOOT_TIMEOUT_MS;" in sessions_src
+    # Always-on retry options live in the base opts object.
+    assert "const sessionRequestOpts={" in refresh
+    assert "retries:1," in refresh
+    assert "retryStatuses:[502,503,504]," in refresh
+
+    boot_gate = refresh.find("if(!_sessionListHasLoadedOnce){")
+    assert boot_gate > 0
+    # The retry options are declared BEFORE the boot-only gate (i.e. unconditional).
+    assert refresh.index("retries:1,") < boot_gate
+    assert refresh.index("retryStatuses:[502,503,504],") < boot_gate
+
+    # Boot-only path still carries the larger timeout + timeout retry.
+    assert "sessionRequestOpts.timeoutMs=_SESSION_LIST_BOOT_TIMEOUT_MS;" in refresh
+    assert refresh.index("sessionRequestOpts.timeoutMs=_SESSION_LIST_BOOT_TIMEOUT_MS;") > boot_gate
+    assert "sessionRequestOpts.retryTimeouts=true;" in refresh
+    assert refresh.index("sessionRequestOpts.retryTimeouts=true;") > boot_gate
+
     assert "const sessData = await api('/api/sessions' + sessionListQS,sessionRequestOpts);" in helper
     assert "api('/api/sessions' + sessionListQS,{timeoutToast:false})" not in helper
-    assert "sessionRequestOpts.retryTimeouts=true" in sessions_src
-    assert "sessionRequestOpts.retryStatuses=[502,503,504]" in sessions_src
     assert "retryTimeouts" in workspace_src
     assert "retryStatuses" in workspace_src