My preferred music site is YouTube music, and I would like to download my liked music playlist to listen to offline, I could do it one by one, But it's over 300 songs at this point.
I ran into a similar issue where I thought I couldn't download playlists. Just check the URL I reckon it did something funny like changing to YouTube music or something.. with the correct URL you should be fine (granted my last download was probably a couple of months ago)
Edit: I just saw your other post about YT music playlist. Ignore this comment