I sent in a trouble report in a verb quiz, selecting “trouble with the last question.” After I finished submitting the issue, I’m on the screen you see below. The device back button returns the submission form and the text mentions “closing the window/tab”, but there’s no UI for doing that. Adding a close button or switching to an alert (more app-like) could resolve this. There’s no obvious way to get back to the app from this point without backing up through the submission dialog.
Android 11, Pixel 2