diff --git a/src/renderer/src/components/sidebar/WorktreeCardAgents.activation.test.tsx b/src/renderer/src/components/sidebar/WorktreeCardAgents.activation.test.tsx
index 4cf81f263fe..422a7089432 100644
--- a/src/renderer/src/components/sidebar/WorktreeCardAgents.activation.test.tsx
+++ b/src/renderer/src/components/sidebar/WorktreeCardAgents.activation.test.tsx
@@ -51,6 +51,8 @@ function mockAgent({
 let mockAgents: DashboardAgentRowData[] = []
 let mockAgentActivityDisplayMode: 'compact' | 'full' | undefined
 let mockTabsByWorktree: Record<string, { id: string }[]> = {}
+let mockTerminalLayoutsByTabId: Record<string, unknown> = {}
+let mockPtyIdsByTabId: Record<string, string[]> = {}
 let mockStructuredTabIds = new Set<string>()
 let mockAgentStatusByPaneKey: Record<string, { worktreeId?: string }> = {}
 let mockActiveTabId: string | null = null
@@ -83,8 +85,8 @@ function buildMockStoreState(): Record<string, unknown> {
     setActiveTab: mockSetActiveTab,
     setActiveTabType: mockSetActiveTabType,
     tabsByWorktree: mockTabsByWorktree,
-    terminalLayoutsByTabId: {},
-    ptyIdsByTabId: {},
+    terminalLayoutsByTabId: mockTerminalLayoutsByTabId,
+    ptyIdsByTabId: mockPtyIdsByTabId,
     runtimePaneTitlesByTabId: {},
     sendPromptToSidebarAgentTarget: vi.fn(),
     settings: {
@@ -173,6 +175,8 @@ describe('WorktreeCardAgents activation', () => {
     mockAgents = []
     mockAgentActivityDisplayMode = undefined
     mockTabsByWorktree = {}
+    mockTerminalLayoutsByTabId = {}
+    mockPtyIdsByTabId = {}
     mockStructuredTabIds = new Set()
     mockAgentStatusByPaneKey = {}
     mockActiveTabId = null
@@ -183,6 +187,54 @@ describe('WorktreeCardAgents activation', () => {
     )
   })
 
+  it.each([
+    ['opens a retained row whose exact pane still has a live PTY', ['pty-a'], true],
+    ['keeps a retained row inert when its pane PTY is no longer live', [], false]
+  ])('%s (#20803)', async (_name, livePtyIds, shouldActivate) => {
+    mockAgentActivityDisplayMode = 'full'
+    const tabId = 'retained-tab'
+    const paneKey = makePaneKey(tabId, LEAF_A)
+    mockAgents = [
+      {
+        ...mockAgent({ paneKey, tabId, agentType: 'codex', prompt: 'Idle', worktreeId: 'wt-1' }),
+        rowSource: 'retained',
+        state: 'done'
+      }
+    ]
+    mockTabsByWorktree = { 'wt-1': [{ id: tabId }] }
+    mockTerminalLayoutsByTabId = {
+      [tabId]: {
+        root: {
+          type: 'split',
+          direction: 'vertical',
+          first: { type: 'leaf', leafId: LEAF_A },
+          second: { type: 'leaf', leafId: LEAF_B }
+        },
+        activeLeafId: LEAF_B,
+        expandedLeafId: null,
+        ptyIdsByLeafId: { [LEAF_A]: 'pty-a', [LEAF_B]: 'pty-b' }
+      }
+    }
+    mockPtyIdsByTabId = { [tabId]: [...livePtyIds, 'pty-b'] }
+    const { default: WorktreeCardAgents } = await import('./WorktreeCardAgents')
+
+    renderToStaticMarkup(<WorktreeCardAgents worktreeId="wt-1" />)
+    capturedRowActivations[0].onActivate(tabId, paneKey)
+
+    if (shouldActivate) {
+      expect(activationMocks.activateAndRevealWorktree).toHaveBeenCalledWith('wt-1')
+      expect(activationMocks.activateTabAndFocusPane).toHaveBeenCalledWith(
+        tabId,
+        LEAF_A,
+        expect.anything()
+      )
+    } else {
+      expect(activationMocks.activateAndRevealWorktree).not.toHaveBeenCalled()
+      expect(activationMocks.activateTabAndFocusPane).not.toHaveBeenCalled()
+    }
+    expect(staleAgentRowMocks.dismissStaleAgentRowByKey).not.toHaveBeenCalled()
+  })
+
   it('activates a projected structured session row through the unified tab path', async () => {
     mockAgentActivityDisplayMode = 'full'
     const tabId = 'structured-tab'
diff --git a/src/renderer/src/components/sidebar/WorktreeCardAgents.test.tsx b/src/renderer/src/components/sidebar/WorktreeCardAgents.test.tsx
index 058ecf07d15..255317e16bd 100644
--- a/src/renderer/src/components/sidebar/WorktreeCardAgents.test.tsx
+++ b/src/renderer/src/components/sidebar/WorktreeCardAgents.test.tsx
@@ -396,19 +396,6 @@ describe('WorktreeCardAgents', () => {
     expect(markup).toContain('data-pane-key="tab-1:2"')
   })
 
-  it('keeps retained completion rows passive when activated', async () => {
-    mockAgentActivityDisplayMode = 'full'
-    mockAgents = [mockAgent({ rowSource: 'retained', state: 'done' })]
-    const { default: WorktreeCardAgents } = await import('./WorktreeCardAgents')
-
-    renderToStaticMarkup(<WorktreeCardAgents worktreeId="wt-1" />)
-    expect(capturedRowActivations).toHaveLength(1)
-    capturedRowActivations[0].onActivate('tab-1', 'tab-1:1')
-
-    expect(activationMocks.activateAndRevealWorktree).not.toHaveBeenCalled()
-    expect(activationMocks.activateTabAndFocusPane).not.toHaveBeenCalled()
-  })
-
   it('shows orchestration child agent rows under their parent by default', async () => {
     mockAgentActivityDisplayMode = 'full'
     mockAgents = [
diff --git a/src/renderer/src/components/sidebar/WorktreeCardAgents.tsx b/src/renderer/src/components/sidebar/WorktreeCardAgents.tsx
index 696ad0928ee..d10162348cc 100644
--- a/src/renderer/src/components/sidebar/WorktreeCardAgents.tsx
+++ b/src/renderer/src/components/sidebar/WorktreeCardAgents.tsx
@@ -29,6 +29,7 @@ import { useWorktreeAgentExpansionState } from './worktree-card-agents-expansion
 import { translate } from '@/i18n/i18n'
 import { activateStructuredAgentSessionTab } from '@/lib/agent-session/structured-agent-session-tab-activation'
 import { selectAgentRowsUnread } from './worktree-card-agent-ack-inputs'
+import { stablePaneHasLivePty } from '@/lib/sleeping-agent-pane-ownership'
 
 export const SUPPRESS_WORKTREE_LIST_SCROLL_ADJUSTMENT_EVENT =
   'orca-suppress-worktree-list-scroll-adjustment'
@@ -185,9 +186,26 @@ const WorktreeCardAgentsBody = React.memo(function WorktreeCardAgentsBody({
     },
     [worktreeId]
   )
-  const handleActivateRetainedAgent = useCallback(() => {
-    // Retained rows are completion evidence; activation would resume sleeping sessions, so keep them inert.
-  }, [])
+  const handleActivateRetainedAgent = useCallback(
+    (tabId: string, paneKey: string) => {
+      const parsed = parsePaneKey(paneKey)
+      const state = useAppStore.getState()
+      // Retained rows are completion evidence; only open a still-live pane so a sleeping target pane is never resumed.
+      if (
+        parsed?.tabId === tabId &&
+        state.tabsByWorktree[worktreeId]?.some((tab) => tab.id === tabId) &&
+        stablePaneHasLivePty(
+          tabId,
+          parsed.leafId,
+          state.ptyIdsByTabId,
+          state.terminalLayoutsByTabId[tabId]
+        )
+      ) {
+        handleActivateAgentTab(tabId, paneKey)
+      }
+    },
+    [handleActivateAgentTab, worktreeId]
+  )
 
   const now = useNow(30_000)
   const { rootRows: rootAgents, childrenByParentPaneKey } = useMemo(