incarnation of dread doesn't phase

I went to fight the incarnation of dread, did the first two phases fine until last phase where the game tells you to take blue rose which I did and then go to the boss which I also did but it just got stuck. Decided, you know what, maybe I need the red one too. The game quest tells me to bring the rose to the boss but nothing happens when I do. I'm just stuck in an endless phase.

Tried to die to reset, nothing happened again.