Inside Bastion of Souls at the top of the stairs after the boss healing the injured Basitkan and defending him from the bugs. In the doorway at the top of the stairs, looking out back down the stairs there is a visual bug shown in the screenshot below.
Not only does this visual bug happen, my frame rates also drop from 60 to about 5 until I pan my camera in a different direction and it puts me back at 60 frames.
I've tried relogging, relaunching my client, restarting PC. None of that worked. It's there in every single run, too.