Redirect causes content collapse (empty state) instead of showing a loader

[GlebKodrik]

To Reproduce

1. Start the app with next dev
2. On the page, click the "GO TO CHECK" button
3. You will first see "TEST LOADING..."
4. Then the page content collapses (shows an empty state/blank screen)
5. Finally, the target page content (from gleb) is displayed
   Current vs. Expected behavior
   Current Behavior
   After triggering a redirect with redirect from next/navigation, the UI briefly collapses to an empty state before rendering the redirected content. This looks like a freeze or glitch. The issue happens both in development and after running a production build.

Expected Behavior
Instead of collapsing to an empty state, the app should keep showing a loader (or any fallback UI) until the redirected page is fully rendered. The transition should feel smooth without a "flash of nothing".

#83830