Blooming Field Boss Bug T15 Map

My friend and I are playing Mortar Cannon Totem builds.

We were fighting the Blooming Field Boss (The bell guy from Act 1) and we were trying to see if we could kill him before he got to the first door. We bugged him out so he went invincible but was still trying to attack us, I guess we canceled him out of his cutscene / animation to move to the next phase.

The map was then unable to be completed, we couldn't do anything but log out and back in at our hideout.

seen this happen twice tonight.

Didn't insta phase him, just regular crossbow attack, and it still happens.

No way but to exit to login screen and force loading into town/hideout.

Map gets completely bricked.