I had a team run today using multi attack and I had to cancel it and then eventually end the battle when I came back from outside and noticed that my Coldheart was not being revived, over many many rounds. I had this as my team and I use windows 11 to play.

Stage 17 - Spirit Keep 

Wight Queen Ankhora - Leader

He Man

Skeletor

Coldheart

Reliquary Tender

(note: I cannot beat the boss here without Coldheart's Reduce Heal debuff, so it was literally just stuck in a non-stop loop since she was not being revived by either revivers)