The Ruler of Highgate bug

This is the first time posting a bug I encountered. I didnt find this bug in the forums. The boss in the quest The Ruler of Highgate, became invisible and I was unable to attack it, all the trash mobs were killed and the cyclones subsided but I still couldn't target or attack her. I had to portal back to town and come back, then I could attack her for a few seconds before the same problems appeared I did this until I killed her.

Same Problem here
https://imgur.com/a/am7nCSJ