Today I’ve had this for the first time but it doesn’t seem like a constant occurrence as it only happened on 2 out of 4 characters I ran the dungeon event with. I have also been running this in over the first three days of the event with several toons and have never before experienced this.
It might have something to do with to do with the order of killing, in a sense of the number of coloured pools a specific mob gets to cast on the ground in total before dying, or it might be entirely time progression based regardless of who dies first and last and with how messed up the level scaling is, some kills take much longer than others.
Anyways, my FPS starts locked at 140 despite being able to go three times as high and this bug cuts it in half the moment of the pull. It may have something to do with the unusually long kill but after around 30 seconds and some 4 pools on the ground FPS tanks down to a single digit number where the game becomes completely unplayable.
Following a kill the green and purple pools disperse almost immediately but afterwards it takes almost 10 seconds per 5 FPS to climb back up and recover with literally nothing happening on the screen. Eventually over a minute or longer FPS will return back to the 140 and if I double the FPS lock, it could take even longer to climb back to 240.
https://i.imgur.com/9Qtxlow.jpeg dropped fps
https://i.imgur.com/9HDDId1.jpeg recovered fps
https://eu.forums.blizzard.com/en/wow/t/crown-chemical-company-dungeon-event-total-lag-out/495624
https://us.forums.blizzard.com/en/wow/t/crown-chemical-co-frame-rate-crash/1516727
https://us.forums.blizzard.com/en/wow/t/crown-chemical-co-instance/99985
https://old.reddit.com/r/wotlk/comments/1amzaby/love_is_in_the_air_apothecary_hummel_lag/
I have whispered players from the group if the same had happened to them and three of them confirmed it for me so I would assume the entire party was affected. I’m playing on an older PC so I may have been hit the hardest.
After more testing I’m starting to think it’s caused by some object that players interact with. It could have something to do either with the fountain or the boxes and players jumping on them.