Ashar Sand Pit bugged at 1HP outside de Boss Room

Hi, I finally made it to Ashar Sand Pit and it bugged out of the room when he was literally 1HP. I can't believe it, after all the struggle to get there. Can u help me in any way please? Im so angry right now, and dont wanna repeat the process all over again. Any kind of compensation?

I've added a screenshot of the boss right behind the exit door on the email i sent, but they told me to post the problem here, so...

Thank you. Player name is: Txonda