Villagers disappear when sleeping

When ever it becomes night and the villagers go to sleep, they disappear. If I change their profession the particles still show up. Zombies still try to attack them. I don't believe you can interact with the villagers while they are like this. It seems that the villagers push each other into a wall and then disappear.

The only way I have found to make them reappear is to either re-log, or go to sleep myself.