Zolin & Zelina heal bug

Fighting Zolin & Zelina can kill Zolin but then Zelina is constantly healing up off of him despite him being dead, he's still making voice lines throughout the fight and I am doing up to 8m+ dmg to her over the course of the fight not sure if intentional or missing something but seems to be bugged or overtuned in some way

This was happening in a two-man party and once I went to a single player reloaded instance I one shot them both within 60 seconds so perhaps related to co-op

Had this happen last night solo. I noticed that not only was he healing to full every 5-10 seconds but also I couldn't do more than about 25% of his hp. I smacked him down to about 25% with 50-100 combo culmination and when he wasn't going down I tried a 1000 combo culmination and it was about the same, should have easily been a 1-shot.

This leads me to believe he is getting stuck in a phase transition, likely due to defeating the melee one while he is using his healing skill or something similar.

Same here in solo. I have do a lot of try but always the same bug. I kill Zélina but Zolin can always drain life on her. So, I can't beat Zolin because is always full life.