Firefox 116.0 (33174) Still not fixed.

Hey there! It sounds like you're facing an issue where video playback continues even after you close a tab in Firefox on your iPad. That can be a bit annoying, but no worries, we'll get it sorted out. This might be due to a glitch in the current version. What you can try is clearing your browser's cache and cookies, and then restarting Firefox. If that doesn't do the trick, you might want to consider updating to the latest version of Firefox or checking if there's any available iPadOS updates. If the issue persists, feel free to reach out to our support community, and we'll be more than happy to assist you further.

Update of Firefox to version 116.1 (33291) fixed this issue.