The extension stopped working due to youtube getting more bloated and slower every update, making the function fire before the miniplayer loads fully, I addressed the issue in the last patch, now it should work almost* always. If you're looking for an extension that wasn't coded at 3am with minimal effort because of a grudge against YT, checkout: https://addons.mozilla.org/en-US/firefox/addon/dopamine-free-youtube/ . An extension that I actually put some time into maintaining. (and it even blocks the miniplayer as well). But thanks for the review/feedback, haven't noticed it stopped working.

Yeah changing it to YouTube instead of YT is a good idea. And btw I tried testing blocking www.youtube.com##ytd-miniplayer with UblockOrigin filters and it managed to not show the actual miniplayer window, but the sound from the previous video kept playing so would need to manually turn that off anyway, so gonna keep how it is for now since then I'd have to make two versions of the extention since I think (not sure) that I can't intercept traffic from that with the V3 manifest. PS: Thanks for the feedback, always appreciated.

Happy to help with something that should just be an option on the settings lol