diff --git a/apps/web/src/app/(sandbox)/sessions/[sessionId]/SessionWorkspace.client.test.tsx b/apps/web/src/app/(sandbox)/sessions/[sessionId]/SessionWorkspace.client.test.tsx
index 9bf7413f9..47e5aa335 100644
--- a/apps/web/src/app/(sandbox)/sessions/[sessionId]/SessionWorkspace.client.test.tsx
+++ b/apps/web/src/app/(sandbox)/sessions/[sessionId]/SessionWorkspace.client.test.tsx
@@ -984,25 +984,25 @@ describe('SessionWorkspace', () => {
     expect(screen.getByLabelText('Task prompt task-1')).toHaveFocus();
   });
 
-  it('opens tasks side-by-side when the Tasks rail item is middle-clicked', async () => {
+  it('opens tasks side-by-side without moving focus from the session prompt', async () => {
     renderWorkspace({
       isMobile: false,
       workspaceWidth: 1280,
+      children: <textarea aria-label="Session prompt" />,
       sessionOverride: { tasks: [singleTask, secondTask] },
     });
 
     expect(await screen.findByLabelText('Full task task-1')).toBeVisible();
     fireEvent.click(screen.getByRole('button', { name: 'Close panel task-1' }));
     fireEvent.click(screen.getByRole('button', { name: 'Close panel task-2' }));
-
-    fireEvent(
-      screen.getByRole('button', { name: 'Tasks' }),
-      new MouseEvent('auxclick', { bubbles: true, button: 1 }),
-    );
+    const sessionPrompt = screen.getByLabelText('Session prompt');
+    sessionPrompt.focus();
+    fireEvent.click(screen.getByRole('button', { name: 'Tasks' }));
+    fireEvent.click(screen.getByRole('button', { name: 'Open side-by-side' }));
 
     expect(screen.getByLabelText('Full task task-1')).toBeVisible();
     expect(screen.getByLabelText('Full task task-2')).toBeVisible();
-    expect(screen.getByText('Session transcript')).toBeVisible();
+    expect(sessionPrompt).toHaveFocus();
   });
 
   it('moves focus between visible prompt inputs with Alt+Arrow keys', async () => {
@@ -1050,7 +1050,7 @@ describe('SessionWorkspace', () => {
     expect(sessionPrompt).toHaveFocus();
   });
 
-  it('focuses the first task when several task panels open initially', async () => {
+  it('keeps session prompt focus when task panels open initially', async () => {
     const thirdTask = {
       ...singleTask,
       taskId: 'task-3',
@@ -1059,17 +1059,17 @@ describe('SessionWorkspace', () => {
     renderWorkspace({
       isMobile: false,
       workspaceWidth: 1600,
-      children: <textarea aria-label="Session prompt" />,
+      children: <textarea aria-label="Session prompt" autoFocus />,
       sessionOverride: { tasks: [singleTask, secondTask, thirdTask] },
     });
 
     expect(await screen.findByLabelText('Task prompt task-3')).toBeVisible();
     await waitFor(() =>
-      expect(screen.getByLabelText('Task prompt task-1')).toHaveFocus(),
+      expect(screen.getByLabelText('Session prompt')).toHaveFocus(),
     );
   });
 
-  it('opens and focuses the first task when several delegated tasks start', async () => {
+  it('opens new delegated tasks without moving session prompt focus', async () => {
     const thirdTask = {
       ...singleTask,
       taskId: 'task-3',
@@ -1083,6 +1083,8 @@ describe('SessionWorkspace', () => {
     });
 
     expect(await screen.findByLabelText('Full task task-1')).toBeVisible();
+    const sessionPrompt = screen.getByLabelText('Session prompt');
+    sessionPrompt.focus();
     fireEvent.click(screen.getByRole('button', { name: 'Tasks' }));
     expect(screen.getByRole('heading', { name: 'Tasks' })).toBeVisible();
     act(() => {
@@ -1094,9 +1096,7 @@ describe('SessionWorkspace', () => {
 
     expect(await screen.findByLabelText('Full task task-2')).toBeVisible();
     expect(screen.getByLabelText('Full task task-3')).toBeVisible();
-    await waitFor(() =>
-      expect(screen.getByLabelText('Task prompt task-2')).toHaveFocus(),
-    );
+    await waitFor(() => expect(sessionPrompt).toHaveFocus());
   });
 
   it('replaces the URL-selected task when a task card opens at one-panel capacity', () => {
diff --git a/apps/web/src/app/(sandbox)/sessions/[sessionId]/use-session-workspace-panels.client.test.ts b/apps/web/src/app/(sandbox)/sessions/[sessionId]/use-session-workspace-panels.client.test.ts
index 867761083..a1f96fb54 100644
--- a/apps/web/src/app/(sandbox)/sessions/[sessionId]/use-session-workspace-panels.client.test.ts
+++ b/apps/web/src/app/(sandbox)/sessions/[sessionId]/use-session-workspace-panels.client.test.ts
@@ -107,7 +107,7 @@ describe('sessionWorkspacePanelReducer', () => {
     });
 
     expect(seeded.taskPanelIds).toEqual(['task-2', 'task-3']);
-    expect(seeded.promptFocusTaskId).toBe('task-1');
+    expect(seeded.promptFocusTaskId).toBeNull();
     expect(getOrderedSessionTaskPanelIds(seeded, 'task-1')).toEqual([
       'task-1',
       'task-2',
@@ -138,12 +138,12 @@ describe('sessionWorkspacePanelReducer', () => {
     {
       utilityPanel: null,
       expectedUtilityPanel: null,
-      expectedFocus: 'task-3',
+      expectedFocus: null,
     },
     {
       utilityPanel: { kind: 'tasks' } as const,
       expectedUtilityPanel: null,
-      expectedFocus: 'task-3',
+      expectedFocus: null,
     },
     {
       utilityPanel: { kind: 'info' } as const,
@@ -196,7 +196,7 @@ describe('sessionWorkspacePanelReducer', () => {
       utilityPanel: null,
       taskPanelIds: ['task-1', 'task-3'],
       taskArtifacts: {},
-      promptFocusTaskId: 'task-2',
+      promptFocusTaskId: null,
     });
   });
 
diff --git a/apps/web/src/app/(sandbox)/sessions/[sessionId]/use-session-workspace-panels.ts b/apps/web/src/app/(sandbox)/sessions/[sessionId]/use-session-workspace-panels.ts
index 78daeec73..fa6ba343e 100644
--- a/apps/web/src/app/(sandbox)/sessions/[sessionId]/use-session-workspace-panels.ts
+++ b/apps/web/src/app/(sandbox)/sessions/[sessionId]/use-session-workspace-panels.ts
@@ -136,10 +136,6 @@ export function sessionWorkspacePanelReducer(
       return {
         ...state,
         taskPanelIds,
-        promptFocusTaskId:
-          action.selectedTaskId ??
-          action.taskIds.find((taskId) => taskId !== action.selectedTaskId) ??
-          null,
       };
     }
     case 'add-tasks': {
@@ -157,15 +153,12 @@ export function sessionWorkspacePanelReducer(
         );
         insertionIndex += 1;
       }
-      const shouldFocus =
+      const shouldShowTaskPanels =
         state.utilityPanel === null || state.utilityPanel.kind === 'tasks';
       return {
         ...state,
-        utilityPanel: shouldFocus ? null : state.utilityPanel,
+        utilityPanel: shouldShowTaskPanels ? null : state.utilityPanel,
         taskPanelIds,
-        promptFocusTaskId: shouldFocus
-          ? (action.taskIds[0] ?? state.promptFocusTaskId)
-          : state.promptFocusTaskId,
       };
     }
     case 'open-task': {
@@ -216,7 +209,6 @@ export function sessionWorkspacePanelReducer(
           (taskId) => taskId !== action.selectedTaskId,
         ),
         taskArtifacts: {},
-        promptFocusTaskId: action.selectedTaskId ?? action.taskIds[0] ?? null,
       };
     case 'show-main':
       return {