Hi, we’re really sorry that happened so close to beating the boss and we understand your frustration.
We have been made aware about this issue in the past when the raid originally launched, and we put out an attempted fix around that time and had not seen it reported in a long time so we thought it resolved.
After your report, we looked at the logs and didn’t find any immediate errors, but if you can share the video with us (you can upload it unlisted and PM it to me, or share the link in a PM with us) we will look at it and investigate deeper on what has happened so we that we can get that fixed when we find out what is causing it.