Alchemy Lab Tier 3 Bug

So, it happened to me 4 or 5 times already, I cant kill the boss on Alchemy Lab on Temple cos it doesnt show the button to activate it, tryed relog, do everything and i cant progress my temple, and i have to close it... please fix, Thank you!

Bug Report ID: #3035245564

Im not sure but it might be something related to taking the soul core near the boss first before killing all the creatures in the room

It has never to me since today. 2 runs stuck in this room.
Of curse I have taken the soul core, I've unequipped the headhunter, nothing to do.
I can't activate the boss.

edit : I do temple run since jan first.