Black Raven Encounter Issue – Unable to Progress Past Phase Two Due to Invulnerability Bug

In the campaign or the otherworld encounters, the boss Black Raven sometimes gets stuck in the second phase — it becomes invulnerable and cannot be damaged, making it impossible to progress to the third phase. I'm not sure what triggers this, but please fix it as soon as possible. I suspect it might be related to me applying a freeze ailment on the boss during the transition from phase one to phase two.

In the campaign, I can return to a checkpoint and retry the fight, but what am I supposed to do if this happens in the otherworld? There's no way to redo the fight.