Act 4 final boss bug

Hi after kill boss npc dont move and cant end quest on character OgnioToxic

Don't know if it's the exact same issue OP is talking about, but I'm encountering a bug after defeating the last phase of the act 4 boss. Both Tavakai and the Hooded One are just chilling next to each other, and nothing happens. I've got a screenshot uploaded to Steam showcasing this: https://steamcommunity.com/sharedfiles/filedetails/?id=3625371186

I've had it happen twice in a row now.