1-turn teeth effet lasting 2 turns

Am I crazy or do 1-turn teeth effects sometimes last 2 turns? Is it a known bug/feature? And no, I don't have>!the dentures!<. It's been happening quite a lot in this Wizard run. I have a 2 chests weakens enemies by 1 for 1 turn, and at more than one occasion did enemies remain weakened after my next move. Has this happened to anyone else?