Well this is *** since I even found posts from 2019 detailing this bug: in Veteran normal (non HM mode) when Zaan casts that shield that people need to run in and despite everyone being in it from the second it spawned, we still keep getting killed by the red fields. Does ZOS simply not care about this at all?!
FIX THE BLOODY DUNGEON PLEASE ZOS!
Quick update, we ran the dungeon 2nd time and it worked perfectly fine. The only thing we didn't do this time was use the HM scroll to have a look at mechanics. It seems that HM for this dungeon doesn't work right now.