Not only does there seem to be a problem with the disease, but the mobs are bugged too.
Apparently, the smaller mobs in this dungeon continuously respawn even after we have killed them and passed on to another area. It seems that this started on the pathway up to the final boss.
Even though we cleared our way up to there, they kept spawning behind us and we ended up wiping because of it. Never got a chance to engage the final boss.
When we respawned they showed up at the the respawn cave and killed us again. So a couple of us just ran back to the beginning to get out since we were still in combat due to the respawns and could not use the port out of dungeon feature in order to reset it.
Only one of us made it out. Finally once everyone died again and respawned they also ran out trailed by these respawning mobs until we all could leave the dungeon. Then we were able to reenter and go back to the final boss after the reset.
Resetting the dungeon stopped the constant respawns so we could continue on and engage the final boss. We have no idea what caused this issue since our tank actually had done this dungeon earlier today and never experienced that problem.
Here’s the link to my bug report: Brackenhide Hollow Dungeon - bugged