diff --git a/apps/web/tests/document-preview.e2e.ts b/apps/web/tests/document-preview.e2e.ts
index a89eee406d..0fcecc5b7e 100644
--- a/apps/web/tests/document-preview.e2e.ts
+++ b/apps/web/tests/document-preview.e2e.ts
@@ -1355,6 +1355,13 @@ else process.exit(1);
           { id: '/Applications/Test Player.app', name: 'Test Player', default: false, icon: `data:image/png;base64,${TINY_PNG.toString('base64')}` },
           { id: '/Applications/Other Player.app', name: 'Other Player', default: false, icon: null },
         ]))
+        // Leave the file and come back: the shared association state is discarded when the
+        // last control for a path unmounts, so the marker is read again instead of reused.
+        await openPreviewFile(column, filesTab, preview, 'notes.unknown')
+        await openPreviewFile(column, filesTab, preview, 'clip.mp4')
+        await unsupported.waitFor({ timeout: 15_000 })
+        await emptyOpen.waitFor({ timeout: 15_000 })
+        // Opening the menu settles the re-read association before the labels are compared.
         await prominent.getByRole('button', { name: 'More ways to open' }).click()
         await page.getByRole('menuitem', { name: 'Test Player (default)', exact: true }).waitFor()
         await page.keyboard.press('Escape')
@@ -1362,14 +1369,17 @@ else process.exit(1);
         expect(await headerOpen.getAttribute('aria-label')).toBe('Open in Test Player')
         await compareOrRefreshGolden(join(SNAPSHOT_DIR, 'applications-no-default.expected.md'), await prominent.ariaSnapshot(), MODE)
         const gesturesBefore = (await opened()).length
+        const launchesBefore = (await launched()).length
         await emptyOpen.click()
         await expect.poll(async () => (await opened()).length).toBe(gesturesBefore + 1)
-        // Without an OS-marked default the main action still opens the file instead of revealing it.
-        expect((await opened()).at(-1)).toEqual({ path: clip, action: 'open' })
-        const launchesBefore = (await launched()).length
+        // Without an OS-marked default the main action opens the application this control
+        // names, rather than the OS association (which can prompt or pick another app).
+        expect((await opened()).at(-1)).toEqual({ path: clip, action: 'application' })
+        await expect.poll(async () => (await launched()).length).toBe(launchesBefore + 1)
+        expect((await launched()).at(-1)?.app).toBe(launchTarget)
         await prominent.getByRole('button', { name: 'More ways to open' }).click()
         await page.getByRole('menuitem', { name: 'Test Player (default)', exact: true }).click()
-        await expect.poll(async () => (await launched()).length).toBe(launchesBefore + 1)
+        await expect.poll(async () => (await launched()).length).toBe(launchesBefore + 2)
         expect((await launched()).at(-1)?.app).toBe(launchTarget)
         await expect.poll(async () => (await opened()).length).toBe(gesturesBefore + 2)
         expect((await opened()).at(-1)).toEqual({ path: clip, action: 'application' })
diff --git a/packages/client/ui-open-in-app/src/client/OpenTargetButton.tsx b/packages/client/ui-open-in-app/src/client/OpenTargetButton.tsx
index 12ceaf0191..3d781070e1 100644
--- a/packages/client/ui-open-in-app/src/client/OpenTargetButton.tsx
+++ b/packages/client/ui-open-in-app/src/client/OpenTargetButton.tsx
@@ -92,7 +92,13 @@ export function OpenTargetButton(props: OpenTargetButtonProps): ReactNode {
   const revealDefault = kind === 'file' && preferred === undefined && props.loading !== true
   const primaryLabel = preferred === undefined ? t('path.reveal') : t('open.title', { app: preferred.name })
   const run = (operation: OpenTargetOperation): void => { setMenuOpen(false); act(operation) }
-  const primary = (): void => { run({ kind: revealDefault ? 'reveal' : 'default' }) }
+  const primary = (): void => {
+    if (revealDefault) { run({ kind: 'reveal' }); return }
+    // The Host's default marker is best effort. With none, request the application
+    // this control names instead of letting the OS resolve the association again.
+    if (preferred !== undefined && preferred.id !== defaultId) { run({ kind: 'application', id: preferred.id }); return }
+    run({ kind: 'default' })
+  }
   const icon = props.loading === true && preferred === undefined
     ? <span className={css.skeleton} data-open-target-skeleton aria-hidden="true" style={{ width: props.prominent ? 18 : 13, height: props.prominent ? 18 : 13 }} />
     : revealDefault
diff --git a/packages/client/ui-open-in-app/tests/open-path-action.client.spec.tsx b/packages/client/ui-open-in-app/tests/open-path-action.client.spec.tsx
index 37540e6764..2113cba232 100644
--- a/packages/client/ui-open-in-app/tests/open-path-action.client.spec.tsx
+++ b/packages/client/ui-open-in-app/tests/open-path-action.client.spec.tsx
@@ -202,7 +202,7 @@ it('opens with the first registered application when none is marked default', as
   await act(async () => {})
   const main = screen.getByRole('button', { name: t('open.title', { app: 'Player' }) })
   await act(async () => { fireEvent.click(main) })
-  expect(b.openPath).toHaveBeenLastCalledWith(ABSOLUTE_PATH, 'open', undefined)
+  expect(b.openPath).toHaveBeenLastCalledWith(ABSOLUTE_PATH, 'open', '/Player.app')
   await act(async () => { fireEvent.click(screen.getByRole('button', { name: zh['path.more'] })) })
   expect(screen.getAllByRole('menuitem').map(item => item.textContent)).toEqual(['Player（默认）', zh['path.reveal']])
 })