For a couple of weeks now we’ve had issues of server side lag during Thursdays on our Mythic Denathrius progress.
Here is a video example of the lag: https://streamable.com/xlwkn0
For those that are not aware of the fight mechanics: the Night Hunter lines that you’re supposed to soak are supposed to all come at the same time, but as you can see in the video, the ghosts are charging in at different times, some almost immediately after appearing - giving no time for raid members to help soak the damage.
This only happens on Thursdays.