I've run into this bug three times where abilities and kills that should grant buffs, don't. Phoenix Dive does not grant healing or spawn a Hellion, ability kills don't grant Devour, and kills on the Unwritten Attendants don't grant the dungeon buff. Additionally, weapons disappear from the screen, though that is only a visual bug and the weapons can still be used. The video shows me running into this bug while using an Apotheosis build. I've run into the same bug while running a Karnstein build, and it also causes the Cure and Restoration from melee kills not to register, from all melee sources: charged, uncharged, and glaive melee. This seems to happen in both second and third encounter when the player is taking a long time to complete the encounters. It happened once in second encounter while I was teaching a teammate, and twice in third encounter while going for a solo clear. In all three instances, the boss was less than half HP and I'd been in the encounter for a while when the buffs stopped registering. I've done clears of this dungeon with my more experienced teammates, where we complete encounters much faster, and there were no problems in those instances.