diff --git a/src/web-ui/src/app/components/NavPanel/sections/sessions/SessionsSection.tsx b/src/web-ui/src/app/components/NavPanel/sections/sessions/SessionsSection.tsx
index 0c16d61cbb..0a1fb1cae3 100644
--- a/src/web-ui/src/app/components/NavPanel/sections/sessions/SessionsSection.tsx
+++ b/src/web-ui/src/app/components/NavPanel/sections/sessions/SessionsSection.tsx
@@ -371,16 +371,15 @@ const SessionsSection: React.FC<SessionsSectionProps> = ({
     void orderingRevision;
     return new Set([...flowChatState.sessions.keys()].filter(sessionNavStatusService.isRunning));
   }, [flowChatState.sessions, orderingRevision]);
-  const catalogQueryJson = useMemo(() => {
-    void orderingRevision;
-    return JSON.stringify(workspaceSessionCatalogQuery(workspaceId, sessionOrdering, sessionShow,
-      sessionFilters, sourceAgent, flowChatState.sessions.values(), sessionNavStatusService.getSortTimestamp) ?? null);
-  }, [workspaceId, sessionOrdering, sessionShow, sessionFilters, sourceAgent, flowChatState.sessions, orderingRevision]);
+  const catalogQueryJson = useMemo(() => JSON.stringify(workspaceSessionCatalogQuery(
+    workspaceId, sessionOrdering, sessionShow, sessionFilters, sourceAgent,
+  ) ?? null), [workspaceId, sessionOrdering, sessionShow, sessionFilters, sourceAgent]);
   const captureCatalogQuery = useCallback((query: SessionCatalogQuery) => captureWorkspaceSessionCatalogQuery(
     query, flowChatStore.getState().sessions.values(), sessionNavStatusService.getSortTimestamp,
   ), []);
-  // Capture the view's observed order only when beginning a catalog. Hydration
-  // and streaming must not restart it; a refresh or device switch must rebind it.
+  // Capture the view's observed order only when beginning a catalog. Hydration,
+  // streaming and run starts must not restart it; a refresh or device switch
+  // must rebind it.
   const catalogQuery = useMemo(() => {
     void catalogRefreshVersion;
     void initialMetadataKey;
diff --git a/src/web-ui/src/app/components/NavPanel/sections/sessions/workspaceSessionCatalogQuery.test.ts b/src/web-ui/src/app/components/NavPanel/sections/sessions/workspaceSessionCatalogQuery.test.ts
index b7caf17e9b..d6cfeaa25b 100644
--- a/src/web-ui/src/app/components/NavPanel/sections/sessions/workspaceSessionCatalogQuery.test.ts
+++ b/src/web-ui/src/app/components/NavPanel/sections/sessions/workspaceSessionCatalogQuery.test.ts
@@ -12,7 +12,7 @@ describe('workspace catalog query selection', () => {
   it('pins an already-observed timestamp even while it still matches local metadata', () => {
     const observed = session('observed', { lastFinishedAt: 10 });
     const viewQuery = workspaceSessionCatalogQuery('main', 'updated', 'all',
-      DEFAULT_WORKSPACE_SESSION_FILTERS, 'all', [observed], recency);
+      DEFAULT_WORKSPACE_SESSION_FILTERS, 'all');
     const query = captureWorkspaceSessionCatalogQuery(viewQuery!, [observed], recency);
     // The host can have finished another turn since this local record loaded.
     // Its new timestamp must not choose a different page than the frozen view.
@@ -20,9 +20,6 @@ describe('workspace catalog query selection', () => {
     expect(viewQuery?.sortTimestamps).toBeUndefined();
 
     const hydrated = session('newly-loaded', { lastFinishedAt: 9 });
-    const afterHydration = workspaceSessionCatalogQuery('main', 'updated', 'all',
-      DEFAULT_WORKSPACE_SESSION_FILTERS, 'all', [observed, hydrated], recency);
-    expect(sessionCatalogQueryKey(afterHydration)).toBe(sessionCatalogQueryKey(viewQuery));
     expect(captureWorkspaceSessionCatalogQuery(query, [observed, hydrated], recency).sortTimestamps)
       .toEqual({ observed: 10, 'newly-loaded': 9 });
   });
@@ -47,16 +44,16 @@ describe('workspace catalog query selection', () => {
   it('uses bounded paging for the default view and every source selector', () => {
     for (const source of ['all', 'openbitfun', 'codex', 'zcode']) {
       expect(workspaceSessionCatalogQuery('main', DEFAULT_WORKSPACE_SESSION_VIEW.ordering, 'all',
-        DEFAULT_WORKSPACE_SESSION_FILTERS, source, [], recency)).toEqual({ workspaceId: 'main', ordering: 'updated', source });
+        DEFAULT_WORKSPACE_SESSION_FILTERS, source)).toEqual({ workspaceId: 'main', ordering: 'updated', source });
     }
   });
 
   it('retains the complete legacy projection for name, status, unread, attention and every richer filter', () => {
     for (const ordering of ['name', 'status'] as const) {
-      expect(workspaceSessionCatalogQuery('main', ordering, 'all', DEFAULT_WORKSPACE_SESSION_FILTERS, 'all', [], recency)).toBeUndefined();
+      expect(workspaceSessionCatalogQuery('main', ordering, 'all', DEFAULT_WORKSPACE_SESSION_FILTERS, 'all')).toBeUndefined();
     }
     for (const show of ['unread', 'attention'] as const) {
-      expect(workspaceSessionCatalogQuery('main', 'updated', show, DEFAULT_WORKSPACE_SESSION_FILTERS, 'codex', [], recency)).toBeUndefined();
+      expect(workspaceSessionCatalogQuery('main', 'updated', show, DEFAULT_WORKSPACE_SESSION_FILTERS, 'codex')).toBeUndefined();
     }
     const filters = [
       { hiddenStatuses: ['running'] }, { hiddenEnvironments: ['remote'] },
@@ -65,21 +62,31 @@ describe('workspace catalog query selection', () => {
     for (const filter of filters) {
       expect(workspaceSessionCatalogQuery('main', 'updated', 'all',
         { ...DEFAULT_WORKSPACE_SESSION_FILTERS, ...filter } as typeof DEFAULT_WORKSPACE_SESSION_FILTERS,
-        'all', [], recency)).toBeUndefined();
+        'all')).toBeUndefined();
     }
   });
 
-  it('preserves observed run ordering only within the owning workspace, including isolated worktrees', () => {
+  it('does not restart the view when a session starts running', () => {
+    // The running row moves ahead of rows whose relative order is unchanged,
+    // so the host pages already read for this view remain valid.
+    expect(sessionCatalogQueryKey(workspaceSessionCatalogQuery('main', 'updated', 'all',
+      DEFAULT_WORKSPACE_SESSION_FILTERS, 'all'))).toBe(sessionCatalogQueryKey({
+      workspaceId: 'main', ordering: 'updated', source: 'all',
+    }));
+  });
+
+  it('pins run ordering only within the owning workspace, including isolated worktrees', () => {
     const sessions = [session('historical'), session('running'), session('peer', { workspaceId: 'other' }),
       session('isolated', { workspaceId: 'worktree', projectWorkspaceId: 'main', config: { executionTarget: {
         kind: 'managedWorktree', rootPath: '/project/.worktrees/one',
       } } }), session('linked', { workspaceId: 'worktree', projectWorkspaceId: 'main' })];
     const getTimestamp = (value: Session) => value.sessionId === 'historical' ? recency(value) : 100;
-    const query = workspaceSessionCatalogQuery('main', 'updated', 'all', DEFAULT_WORKSPACE_SESSION_FILTERS, 'all', sessions, getTimestamp);
-    expect(query?.sortTimestamps).toEqual({ running: 100, isolated: 100 });
+    const query = workspaceSessionCatalogQuery('main', 'updated', 'all', DEFAULT_WORKSPACE_SESSION_FILTERS, 'all');
     expect(captureWorkspaceSessionCatalogQuery(query!, sessions, getTimestamp).sortTimestamps)
       .toEqual({ historical: 20, running: 100, isolated: 100 });
-    expect(workspaceSessionCatalogQuery('main', 'created', 'all', DEFAULT_WORKSPACE_SESSION_FILTERS, 'all', sessions, getTimestamp)?.sortTimestamps).toBeUndefined();
-    expect(sessionCatalogQueryKey(query)).toBe(sessionCatalogQueryKey({ ...query!, sortTimestamps: { isolated: 100, running: 100 } }));
+    const created = workspaceSessionCatalogQuery('main', 'created', 'all', DEFAULT_WORKSPACE_SESSION_FILTERS, 'all');
+    expect(captureWorkspaceSessionCatalogQuery(created!, sessions, getTimestamp).sortTimestamps).toBeUndefined();
+    expect(sessionCatalogQueryKey({ ...query!, sortTimestamps: { running: 100, isolated: 100 } }))
+      .toBe(sessionCatalogQueryKey({ ...query!, sortTimestamps: { isolated: 100, running: 100 } }));
   });
 });
diff --git a/src/web-ui/src/app/components/NavPanel/sections/sessions/workspaceSessionCatalogQuery.ts b/src/web-ui/src/app/components/NavPanel/sections/sessions/workspaceSessionCatalogQuery.ts
index b3d6546923..672fead048 100644
--- a/src/web-ui/src/app/components/NavPanel/sections/sessions/workspaceSessionCatalogQuery.ts
+++ b/src/web-ui/src/app/components/NavPanel/sections/sessions/workspaceSessionCatalogQuery.ts
@@ -23,32 +23,19 @@ export function workspaceSessionCatalogTotal(visibleCount: number, catalog: { pa
     ? (catalog.total ?? 0) + visibleCount - (catalog.knownCount ?? visibleCount) : 0);
 }
 
-/** Select supported views and the ordering changes that restart their reader.
- * Newly hydrated rows alone must not invalidate an in-progress catalog. */
+/** Select supported views. Only a view change restarts their reader: a session
+ * that starts running moves ahead of rows whose relative order is unchanged,
+ * so the local projection reorders it without discarding the host pages. */
 export function workspaceSessionCatalogQuery(
   workspaceId: string | undefined,
   ordering: WorkspaceSessionOrdering,
   show: WorkspaceSessionShow,
   filters: WorkspaceSessionFilters,
   source: string,
-  sessions: Iterable<Session>,
-  getSortTimestamp: (session: Session) => number,
 ): SessionCatalogQuery | undefined {
   if (!workspaceId || (ordering !== 'updated' && ordering !== 'created')
     || show !== 'all' || hasWorkspaceSessionFilters(filters)) return;
-  const sortTimestamps: Record<string, number> = {};
-  if (ordering === 'updated') {
-    for (const session of sessions) {
-      if (!sessionBelongsToWorkspaceNavRow(session, workspaceId)) continue;
-      const timestamp = getSortTimestamp(session);
-      if (timestamp !== (session.lastFinishedAt ?? session.createdAt)) {
-        sortTimestamps[session.sessionId] = timestamp;
-      }
-    }
-  }
-  return { workspaceId, ordering, source,
-    ...(Object.keys(sortTimestamps).length ? { sortTimestamps } : {}),
-  };
+  return { workspaceId, ordering, source };
 }
 
 /** Bind every observed timestamp before reading a new host catalog. Matching