Thought I'd throw in a few bugs I have encountered so far in the Microsoft Store preview version in case they aren't part of the known issues on github.
Sometimes the album art thumbnail will update in the default view, however the song name and artist will persist from a previous song after the song change. (Screenshot of this on post)
If there is an error on a song with Apple Music (This occurs on Apple Music web too, but not Apple Music app on iOS / iPad OS etc) on lyric click on these songs error "Failed to fetch" is returned (this is on Apples side, for reference I'm using GB region), however if this occurs on Cider you must then restart the app to change song to one that will play.