This happens to me all the time. It's a known issue which has been reported multiple times; #1375 appears to be the primary issue for this in the UI repo.

I'm the person who reported that. As a temporary workaround I'm using the Favicon Switcher extension (with a smaller file). You have to do it per Firefox instance; the settings aren't synced.

I've found the playlist -- it's called Alone Together. I've just started on the first episode and it's pretty cool. It's a fanfiction radio play!