Caught this bug yesterday. Was winning the raid, enemy only had Magni in ghost mode (Fighter revive talent). Tapped on Baldur to heal him a bit, and suddenly raid crashed with an unexpected error (don’t remember exact wording).
It looks like it counted the raid as “lost” and didn’t count toward Defeat Heroes in Raids mission.
I think the new “attacks random target” addition to Baldur’s special crashes the raid when the only target is in ghost mode.