Fenix: [Bug] White screen when using back swipe to close Firefox Preview and reopening from 'Recents'

[adityamurugan]

Steps to reproduce

1. Close Firefox preview
2. Open external link in Firefox Preview
3. Use back button/back swipe to close Firefox Preview
4. Open Firefox Preview again from 'Recents'

Expected behavior

Firefox Preview should open the home page without any white screens

Actual behavior

Firefox preview shows a blank white screen and need to be closed and opened to fix

Device information

• Android device: Pixel 3a
• Fenix version: Nightly 200312 18.01

[sblatz]

Video of the behavior: https://www.reddit.com/r/firefox/comments/fhsemk/bugfenix_white_screen_when_using_back_swipe_to/

[adityamurugan]

There has been a small change in behavior but the bug is still there.

-The first back swipe closes the external link tab and the home page is shown
-The second back swipe minimizes the app to recents
-Now, trying to reopen the app from the recents drawer shows a white screen.

Version: Nightly 200416 08:30 (Build #21070840)

[sflorean]

Tested on Nightly 6/12 and I was able to reproduce the issue on the following devices, only if the page from step 2 is opened in the browser:

• Google Pixel 3 (Android 11-beta)
• LG G7 FIT (Android 8)
  If I have more than 1 open tabs, the previous open tab is displayed after I open Nightly from Recents.

[abodea]

Verified as fixed on the latest Nightly 6/23 with Google Pixel 4 XL (10).
Note that the home page was displayed in both cases when I had 1 or more tabs open.