diff --git a/apps/desktop/src/app/chat/sidebar/index.tsx b/apps/desktop/src/app/chat/sidebar/index.tsx
index 3268772faa..99d31d6cd2 100644
--- a/apps/desktop/src/app/chat/sidebar/index.tsx
+++ b/apps/desktop/src/app/chat/sidebar/index.tsx
@@ -165,6 +165,7 @@ import {
   ProjectMenu,
   projectTreeCwd,
   reconcileEnteredProjectSessions,
+  sessionBucketId,
   sessionMatchesProjectFilter,
   sessionRecency as sessionTime,
   type SidebarProjectTree,
@@ -1163,6 +1164,27 @@ export function ChatSidebar({
     [projectOverview, agentSessions, projects, removedSessionIds, sortOrderIds, showAllSessions]
   )
 
+  // A row's "Show all" hydrates raw backend lanes, which — like the drill-in —
+  // must go through the same exclusion as the previews above (pins, filter
+  // misses, optimistic removals), or a pinned chat renders twice and a
+  // just-deleted one comes back. The per-project count of loaded sessions
+  // that exclusion hides also corrects the backend's `sessionCount` in the
+  // "Show all N" label (a pin is always loaded — it renders in Pinned).
+  const overviewHidden = useMemo(() => {
+    const isHidden = (session: SessionInfo) => isHiddenFromProjects(session) || removedSessionIds.has(session.id)
+    const counts: Record<string, number> = {}
+
+    for (const session of sessions) {
+      const projectId = isHidden(session) ? sessionBucketId(session, projects) : null
+
+      if (projectId) {
+        counts[projectId] = (counts[projectId] ?? 0) + 1
+      }
+    }
+
+    return { isHidden, counts }
+  }, [sessions, projects, isHiddenFromProjects, removedSessionIds])
+
   const onEnterProject = useCallback(
     (id: string) => {
       const project = projectModel.find(node => node.id === id)
@@ -1857,6 +1879,7 @@ export function ChatSidebar({
                 }
                 projectContent={inProject ? enteredProjectContent : undefined}
                 projectOverview={projectOverview}
+                projectOverviewHidden={overviewHidden}
                 projectOverviewPreviews={overviewPreviews}
                 projectRepoWorktrees={inProject ? scopedRepoWorktrees : undefined}
                 projectsLoading={worktreeGroupingActive ? projectTreeLoading : false}
diff --git a/apps/desktop/src/app/chat/sidebar/projects/index.ts b/apps/desktop/src/app/chat/sidebar/projects/index.ts
index 501ba79cd9..9364b7096f 100644
--- a/apps/desktop/src/app/chat/sidebar/projects/index.ts
+++ b/apps/desktop/src/app/chat/sidebar/projects/index.ts
@@ -16,6 +16,7 @@ export {
   overlayLiveLanes,
   overlayLivePreviews,
   reconcileEnteredProjectSessions,
+  sessionBucketId,
   sessionMatchesProjectFilter,
   sessionRecency,
   type SidebarProjectTree,
diff --git a/apps/desktop/src/app/chat/sidebar/projects/overview-row.test.tsx b/apps/desktop/src/app/chat/sidebar/projects/overview-row.test.tsx
index f8d38ef6b1..825e08cafb 100644
--- a/apps/desktop/src/app/chat/sidebar/projects/overview-row.test.tsx
+++ b/apps/desktop/src/app/chat/sidebar/projects/overview-row.test.tsx
@@ -14,7 +14,7 @@ afterEach(cleanup)
 const workspaceOpen = vi.hoisted(() => ({ value: false }))
 
 const projectsStore = vi.hoisted(() => ({
-  fetchProjectSessions: vi.fn<(id: string) => Promise<null | SidebarProjectTree>>(),
+  fetchProjectSessions: vi.fn<(id: string, options?: { supersedable?: boolean }) => Promise<null | SidebarProjectTree>>(),
   projectProfile: vi.fn<() => null | string>(() => 'default')
 }))
 
@@ -121,10 +121,39 @@ describe('ProjectOverviewRow', () => {
     fireEvent.click(screen.getByRole('button', { name: 'Show all 5 sessions' }))
 
     await waitFor(() => expect(screen.getByTestId('rows').textContent).toBe('s1,s2,s3,s4,s5'))
-    expect(projectsStore.fetchProjectSessions).toHaveBeenCalledWith('p1')
+    expect(projectsStore.fetchProjectSessions).toHaveBeenCalledWith('p1', { supersedable: false })
     expect(screen.queryByRole('button', { name: 'Show all 5 sessions' })).toBeNull()
   })
 
+  // The hydrated lanes are the raw backend payload: pinned, filtered-out and
+  // just-deleted sessions must go through the same exclusion the previews did,
+  // and N must not promise rows the view hides.
+  it('"Show all" runs the hydrated lanes through the tree exclusion and counts only what it will render', async () => {
+    workspaceOpen.value = true
+    const five = Array.from({ length: 5 }, (_, index) => session(`s${index + 1}`, 500 - index))
+    const busy = { ...project, sessionCount: 5 } as SidebarProjectTree
+    projectsStore.fetchProjectSessions.mockResolvedValue({
+      ...busy,
+      repos: [{ groups: [{ sessions: five }] }]
+    } as unknown as SidebarProjectTree)
+    // s2 is pinned (renders in Pinned), s5 was just deleted.
+    const hidden = new Set(['s2', 's5'])
+
+    render(
+      <ProjectOverviewRow
+        hiddenSessionCount={hidden.size}
+        isSessionHidden={item => hidden.has(item.id)}
+        previewSessions={[five[0], five[2]]}
+        project={busy}
+        renderRows={items => <div data-testid="rows">{items.map(item => item.id).join(',')}</div>}
+      />
+    )
+
+    fireEvent.click(screen.getByRole('button', { name: 'Show all 3 sessions' }))
+
+    await waitFor(() => expect(screen.getByTestId('rows').textContent).toBe('s1,s3,s4'))
+  })
+
   it('offers the "new session" add button on Home, which starts one with no folder', () => {
     const home = {
       id: '__no_project__',
diff --git a/apps/desktop/src/app/chat/sidebar/projects/overview-row.tsx b/apps/desktop/src/app/chat/sidebar/projects/overview-row.tsx
index 2a4c1a8c1c..3e8c5f4e9b 100644
--- a/apps/desktop/src/app/chat/sidebar/projects/overview-row.tsx
+++ b/apps/desktop/src/app/chat/sidebar/projects/overview-row.tsx
@@ -26,7 +26,7 @@ import {
 
 import { expandedProjectSessions, latestProjectSessions, PROJECT_PREVIEW_COUNT, useWorkspaceNodeOpen } from './model'
 import { ProjectContextMenu, ProjectMenu } from './project-menu'
-import type { SidebarProjectTree } from './workspace-groups'
+import { excludeProjectSessions, type SidebarProjectTree } from './workspace-groups'
 import { WorkspaceAddButton } from './workspace-header'
 
 // A bare color dot (no icon) or an icon glyph — tinted by `color` when set, else
@@ -81,6 +81,13 @@ interface ProjectOverviewRowProps {
   renderRows?: (sessions: SessionInfo[]) => React.ReactNode
   activeProjectId?: null | string
   previewSessions?: SessionInfo[]
+  /** What the project tree drops (pins, filter misses, just-deleted rows) —
+   *  the same predicate `previewSessions` was built with, so a "Show all"
+   *  hydration can't resurrect them. */
+  isSessionHidden?: (session: SessionInfo) => boolean
+  /** How many of the backend's `sessionCount` that predicate hides, so
+   *  "Show all N" promises only rows the view will actually render. */
+  hiddenSessionCount?: number
   reorderable?: boolean
   dragging?: boolean
   dragHandleProps?: React.HTMLAttributes<HTMLElement>
@@ -96,6 +103,8 @@ export function ProjectOverviewRow({
   renderRows,
   activeProjectId,
   previewSessions,
+  isSessionHidden,
+  hiddenSessionCount = 0,
   reorderable = false,
   dragging = false,
   dragHandleProps,
@@ -118,8 +127,12 @@ export function ProjectOverviewRow({
   const limit = showAllSessions || expanded ? Infinity : PROJECT_PREVIEW_COUNT
   const fetched = (previewSessions ?? []).slice(0, limit)
   const recent = fetched.length ? fetched : latestProjectSessions(project, limit)
-  const preview = renderRows ? (expanded ? expandedProjectSessions(recent, expanded) : recent) : []
-  const hiddenCount = project.sessionCount - preview.length
+  // The hydrated lanes come straight from the backend, so — like the drill-in
+  // (index.tsx) — they haven't been through the tree's exclusion filter yet.
+  const visible = expanded && isSessionHidden ? excludeProjectSessions(expanded, isSessionHidden) : expanded
+  const preview = renderRows ? (visible ? expandedProjectSessions(recent, visible) : recent) : []
+  const total = project.sessionCount - hiddenSessionCount
+  const hiddenCount = total - preview.length
   const offerShowAll = !showAllSessions && !expanded && preview.length > 0 && hiddenCount > 0
 
   const showAll = () => {
@@ -132,7 +145,7 @@ export function ProjectOverviewRow({
     }
 
     setExpanding(true)
-    fetchProjectSessions(project.id)
+    fetchProjectSessions(project.id, { supersedable: false })
       .then(tree => void (tree && setExpanded(tree)))
       .catch(() => onEnter?.(project.id))
       .finally(() => setExpanding(false))
@@ -261,7 +274,7 @@ export function ProjectOverviewRow({
                   </SidebarRowLeadGlyph>
                 </SidebarRowLead>
                 <SidebarRowLabel className="text-xs underline-offset-4 group-hover/more:underline">
-                  {s.projects.showAllCount(project.sessionCount)}
+                  {s.projects.showAllCount(total)}
                 </SidebarRowLabel>
               </SidebarRowBody>
             </SidebarRowShell>
diff --git a/apps/desktop/src/app/chat/sidebar/sessions-section.tsx b/apps/desktop/src/app/chat/sidebar/sessions-section.tsx
index b05d9ab306..17b9117899 100644
--- a/apps/desktop/src/app/chat/sidebar/sessions-section.tsx
+++ b/apps/desktop/src/app/chat/sidebar/sessions-section.tsx
@@ -134,6 +134,10 @@ interface SidebarSessionsSectionProps {
   projectOverview?: SidebarProjectTree[]
   // Per-project preview rows (from the backend tree), keyed by project id.
   projectOverviewPreviews?: Record<string, SessionInfo[]>
+  // The exclusion the previews were built with (pins, filter misses, removed
+  // ids) plus how many of each project's `sessionCount` it hides — applied
+  // again when a row hydrates its full lanes on "Show all".
+  projectOverviewHidden?: { isHidden: (session: SessionInfo) => boolean; counts: Record<string, number> }
   // True while the backend project tree is loading (overview skeleton).
   projectsLoading?: boolean
   onEnterProject?: (id: string) => void
@@ -207,6 +211,7 @@ export function SidebarSessionsSection({
   groups,
   projectOverview,
   projectOverviewPreviews,
+  projectOverviewHidden,
   projectsLoading = false,
   onEnterProject,
   projectContent,
@@ -513,6 +518,8 @@ export function SidebarSessionsSection({
     const projectRow = (project: SidebarProjectTree, Component: typeof ProjectOverviewRow) => (
       <Component
         activeProjectId={activeProjectId}
+        hiddenSessionCount={projectOverviewHidden?.counts[project.id]}
+        isSessionHidden={projectOverviewHidden?.isHidden}
         key={project.id}
         onEnter={onEnterProject}
         onNewSession={onNewSessionInWorkspace}
diff --git a/apps/desktop/src/store/projects.ts b/apps/desktop/src/store/projects.ts
index 1a51ff25da..47693451c9 100644
--- a/apps/desktop/src/store/projects.ts
+++ b/apps/desktop/src/store/projects.ts
@@ -522,8 +522,15 @@ async function refreshProjectTreeAcrossProfiles(): Promise<void> {
 // membership match exactly.
 let projectSessionsRefreshGeneration = 0
 
-export async function fetchProjectSessions(projectId: string): Promise<SidebarProjectTree | null> {
-  const generation = ++projectSessionsRefreshGeneration
+// A drill-in only wants the LATEST request (an older one resolving late would
+// paint the wrong project), so those are `supersedable` and resolve null when
+// overtaken. A per-row "Show all" expansion is not: two rows expanding at once,
+// or a drill-in elsewhere, must not silently leave the first row collapsed.
+export async function fetchProjectSessions(
+  projectId: string,
+  { supersedable = true }: { supersedable?: boolean } = {}
+): Promise<SidebarProjectTree | null> {
+  const generation = supersedable ? ++projectSessionsRefreshGeneration : null
   const profile = projectProfile()
 
   if (!profile) {
@@ -541,14 +548,14 @@ export async function fetchProjectSessions(projectId: string): Promise<SidebarPr
       projectParams({ project_id: projectId }, context.profile)
     )
 
-    if (generation !== projectSessionsRefreshGeneration || !stillOnProjectsContext(context)) {
+    if ((generation !== null && generation !== projectSessionsRefreshGeneration) || !stillOnProjectsContext(context)) {
       return null
     }
 
     return res.project ?? null
   } catch (error) {
     if (
-      generation !== projectSessionsRefreshGeneration ||
+      (generation !== null && generation !== projectSessionsRefreshGeneration) ||
       profile !== projectProfile() ||
       (context && !stillOnProjectsContext(context))
     ) {