diff --git a/.changeset/26737-studio-selection-unfolds-panel.md b/.changeset/26737-studio-selection-unfolds-panel.md
new file mode 100644
index 00000000000..84d8a2a8934
--- /dev/null
+++ b/.changeset/26737-studio-selection-unfolds-panel.md
@@ -0,0 +1,17 @@
+---
+'@object-ui/app-shell': patch
+---
+
+fix(app-shell): in Studio, selecting an element while the right panel is hidden unfolds the panel on its properties
+
+Clause-②: no
+Metadata-protocol: none
+
+With the right panel hidden from the top bar, selecting a flow node in Automations (or a block in Interfaces, or a field in Data) showed its configuration nowhere on a desktop-width screen: only a phone reopened the panel. A builder had to find the toggle again before they could edit the selected step.
+
+What changes:
+
+- A new selection now unfolds a hidden panel at every width, on the selected element's properties, the way `⌘.` unfolds it. The panel's shown state is remembered as when you show it from the toggle.
+- Hiding the panel again while the same element stays selected keeps it hidden. Only another selection unfolds it.
+
+What to do: nothing. Nothing a flow, page or object declares changes.
diff --git a/ui/packages/app-shell/src/views/studio-design/StudioDesignSurface.pillarsClaimSlot-12725.test.tsx b/ui/packages/app-shell/src/views/studio-design/StudioDesignSurface.pillarsClaimSlot-12725.test.tsx
index a7d18781266..34ff0e4debb 100644
--- a/ui/packages/app-shell/src/views/studio-design/StudioDesignSurface.pillarsClaimSlot-12725.test.tsx
+++ b/ui/packages/app-shell/src/views/studio-design/StudioDesignSurface.pillarsClaimSlot-12725.test.tsx
@@ -17,7 +17,8 @@
  *    returns it to the flow's Configuration. A row too narrow for the classic
  *    aside opens no drawer (objectui#11795's fold is the classic layout's).
  *  - While 属性 shows, the copilot strip stays at the slot's foot.
- *  - A hidden slot stays hidden on a selection, as on Interfaces.
+ *  - A hidden slot unfolds on a new selection (objectstack#26737); hidden again
+ *    over the same selection, it stays hidden.
  *  - CONTROL: the Access pillar claims nothing — the slot shows the copilot
  *    alone; the Interfaces pillar's own pins live in `rightSlot-12725`.
  *
@@ -383,19 +384,39 @@ describe('Automations: the Configuration is in the right slot (objectui#12725)',
     }
   });
 
-  it('a hidden slot stays hidden on a selection, as on Interfaces', async () => {
-    window.sessionStorage.setItem(DOCK_STUDIO_EXPANDED_STORAGE_KEY, '0');
+  // objectstack#26737 — at a desktop width (no `md` match), a node selected
+  // while the panel is hidden unfolds it on that node's configuration.
+  it('a hidden slot unfolds on a selection, on the selected node’s configuration', async () => {
     await openFlow();
+    fireEvent.click(screen.getByTestId('studio-slot-toggle'));
     expect(slot()).not.toBeVisible();
+    expect(window.sessionStorage.getItem(DOCK_STUDIO_EXPANDED_STORAGE_KEY)).toBe('0');
 
     fireEvent.click(screen.getByTestId('pick-node'));
-    await act(async () => {});
-    expect(slot()).not.toBeVisible();
+    await waitFor(() => expect(slot()).toBeVisible());
+    expect(slot()).toHaveAttribute('data-mode', 'props');
+    expect(within(slotProps()).getByLabelText('Node start')).toBeVisible();
+    expect(screen.getByTestId('studio-slot-toggle')).toHaveAttribute('aria-pressed', 'true');
+    expect(window.sessionStorage.getItem(DOCK_STUDIO_EXPANDED_STORAGE_KEY)).toBe('1');
     expect(screen.queryByTestId('auto-config-drawer')).toBeNull();
-    // Shown again, it opens on the selection's properties.
+  });
+
+  it('hidden again over the same selection, it stays hidden until another node is selected', async () => {
+    await openFlow();
+    fireEvent.click(screen.getByTestId('pick-node'));
+    await waitFor(() => expect(within(slotProps()).getByTestId('stub-flow-inspector')).toBeVisible());
+
     fireEvent.click(screen.getByTestId('studio-slot-toggle'));
-    expect(slot()).toHaveAttribute('data-mode', 'props');
-    expect(within(slotProps()).getByTestId('stub-flow-inspector')).toBeVisible();
+    await act(async () => {});
+    expect(slot()).not.toBeVisible();
+    // The same node again is no new selection.
+    fireEvent.click(screen.getByTestId('pick-node'));
+    await act(async () => {});
+    expect(slot()).not.toBeVisible();
+
+    fireEvent.click(screen.getByTestId('pick-other-node'));
+    await waitFor(() => expect(slot()).toBeVisible());
+    expect(within(slotProps()).getByLabelText('Node end')).toBeVisible();
   });
 });
 
diff --git a/ui/packages/app-shell/src/views/studio-design/StudioDesignSurface.rightSlot-12725.test.tsx b/ui/packages/app-shell/src/views/studio-design/StudioDesignSurface.rightSlot-12725.test.tsx
index aee0b100806..932b3fb721f 100644
--- a/ui/packages/app-shell/src/views/studio-design/StudioDesignSurface.rightSlot-12725.test.tsx
+++ b/ui/packages/app-shell/src/views/studio-design/StudioDesignSurface.rightSlot-12725.test.tsx
@@ -267,6 +267,19 @@ describe('Studio right slot: properties OR the copilot (objectui#12725)', () =>
     expect(window.sessionStorage.getItem(DOCK_STUDIO_EXPANDED_STORAGE_KEY)).toBe('1');
   });
 
+  // objectstack#26737 — a selection is never drawn nowhere: at a desktop width
+  // it unfolds a hidden slot on the selected block's properties.
+  it('selecting a block while the slot is hidden unfolds it on the properties', async () => {
+    await openDashboard();
+    fireEvent.click(screen.getByTestId('studio-slot-toggle'));
+    expect(slot()).not.toBeVisible();
+
+    fireEvent.click(screen.getByTestId('pick-block'));
+    await waitFor(() => expect(slot()).toBeVisible());
+    expect(slot()).toHaveAttribute('data-mode', 'props');
+    expect(within(slotProps()).getByTestId('stub-inspector')).toBeVisible();
+  });
+
   it('the copilot tab and strip mark a plan that awaits approval', async () => {
     copilot.planPending = true;
     await openDashboard();
diff --git a/ui/packages/app-shell/src/views/studio-design/StudioDesignSurface.tsx b/ui/packages/app-shell/src/views/studio-design/StudioDesignSurface.tsx
index 8df83030071..e3ba37b0f9a 100644
--- a/ui/packages/app-shell/src/views/studio-design/StudioDesignSurface.tsx
+++ b/ui/packages/app-shell/src/views/studio-design/StudioDesignSurface.tsx
@@ -1807,10 +1807,19 @@ export function StudioDesignSurface({ aiSlot }: StudioDesignSurfaceProps): React
     setSlotPropsClaims((n) => n + 1);
     return () => setSlotPropsClaims((n) => n - 1);
   }, []);
-  const showSlotProps = React.useCallback(() => {
+  // objectstack#26737 — a selection shows its properties at every width: a
+  // hidden slot unfolds, as `⌘.` unfolds it, so a builder who hid the panel is
+  // never left with a selection whose properties are drawn nowhere. One
+  // function for the surface's life (state, not a memo — AGENTS.md #10): the
+  // pillars ask on a new selection only, never because this was re-created.
+  const setSlotOpenRef = React.useRef(setSlotOpen);
+  React.useLayoutEffect(() => {
+    setSlotOpenRef.current = setSlotOpen;
+  });
+  const [showSlotProps] = React.useState(() => () => {
     setSlotMode('props');
-    if (isMobile) setSlotOpenMobile(true);
-  }, [isMobile]);
+    setSlotOpenRef.current(true);
+  });
   const slotHandle = React.useMemo<StudioRightSlotHandle | null>(
     () =>
       slotHost