The main menu Music played till the end,, now nothing plays, is that ok
Blank screen: can you please provide the steps to reproduce since I can't quite do it myself, unfortunately
Music: apparently there's another bug with exporting into Web version - if you like to play the music again just hit the SFX button once it's stopped
Sorry for the bugs but yeah. Sad that I couldn't foresee them since there was no problems with exporting on previous Godot versions