2022-01-24: Found water under a mattress at the rental
Not this :/
Due to the rushing of moving, we had not yet moved any bed frames, we just had 3 mattresses on the floor. I put poly under the big mattress to make it easier to move around in the room - and randomly I happened to notice that water was collecting under the poly!After more investigation, all the mattresses had water under them, and one of them had the tiniest bit of mold