My villagers keep despawning

Villagers can despawn, even if they have a profession and leveled up. It appears to occur when you rejoin set world, half of the time, one villager at a time. It’s getting very frustrating having to keep releveling up my villagers because they keep despawning. Please fix this.
*This bug is also in 1.17.10, the ‘affected versions’ tab won’t cooperate.