Since the bug fix for Realms crashing (REALMS-6812) we are seeing a consistent issue.

We have only noticed it at night, but in the morning when villagers wake up several of them disappear, villagers immediate create babies to replace them. 

This appears to be the case across the realm and not just a single town. 

The town I play in has 20 villagers and in the morning 5 of them are missing.

Like waking up in an M. Night Shyamalan movie.  In the morning, the parents are replaced with babies

Occurs regardless of if the player sleeps or is awake