Floating villagers in beds

When villagers sleep they start to move arround and float halv a block above their beds, and if multiple beds are next to eachother (like in a villager breeder) they will start to slide sideways and connect on the middle where the beds connect. It seems to happen at random as I can not seem to find a logical way to when or how this happens, some days they do this, while other days they lie where they are suppose to be.