Bug: Emptying trash overlay on main screen can become stuck and unable to do anything else IN THAT WEB PAGE,
User action that exposes the problem:

1. Select Trash folder,
2. Empty trash (screen overlaid with Emptying Trash progress bar at top)
3. Without waiting for it to finish (USER ERROR) Select SPAM folder
4. Empty Spam ... wait for it to finish.
5. Re-select Trash folder. Screen re-displays Empty Trash progress bar at top) but never finishes.

6. NO MOVEMENT OF THE TRASH FOLDER DISPLAY. The Browser(Firefox 149.0.2 (64-bit) with GMail Web app reading/displaing YahooMail+). Display of YahooMail+ connection is frozen, although other pages in the browser may be manipulated as usual, including using Gmail app in other browser pages to read and manipulate Google Mail).

7. Recovery: close the frozen YahooMail display page, then reconnect to YahooMail+.

Possible factor: Trash folder typically has < 10 entries, while Spam Folder collects 30+ emails a day. So it's possible the trash folder has finished emptying while the Spam Folder is being emptied.

Suspiscion: Your user interface code checks for non-zero messages in Trash and/or Spam folders when first selecting Empty Trash or Spam and won't start if the folder content count is zero, but if the user doesn't wait for background deletion in that folder and instead switches to another folder and then returns to the original folder AND that folder has been emptied IN THE BACKGROUND in the meantime, the re-display of the progress overlay FAILS to check for zero contents and redisplays the progress bar with nothing to do but no way to exit. At this point, this web page display is in what I call "Mumble Mode" and cannot be interrupted.