It takes two bug(?) with Mays power (singing)

We were playing chapter on Attic called "Rehearsal" and Mays power does'nt prompt/work after we unlock the door (break the tapes with Codys drum disc power and unlock the door with Mays singing power) - what could be the issue and how do we fix it? We want to continue so bad this game, but we've already tried many things as restarting the computer, checking all the updates and verifying integrity of game files but nothing seems to work. We also tried if it makes any difference if we use inviting on steam or EA, but nope. Didn't change even if we changed characters.