Edit: Disregard my original reply, updated today and now it works again lol!

It launches for me (and I am in a plasma-wayland session FWIW), and it loads the thumbnails for all videos with no problem. When I click a video as if to play it, it appears to load up the main page for that video complete with play button, but nothing at all happens when I click the play button. Along the way are various api errors from youtube, but I think some of those came in even when things were working for me.

Basically I can get this far for any video: