We have no post-handling should we fail to enter PiP, as such we have things left in a broken state with a transparent UIWindow having the focus and preventing the main UI to receive events, making Safari appears to be hung.
rdar://99055598
Pull request: https://github.com/WebKit/WebKit/pull/3800
Committed 253974@main (14c0a0df4180): <https://commits.webkit.org/253974@main> Reviewed commits have been landed. Closing PR #3800 and removing active labels.