I play on Bedrock for Switch.
I've had my world for about one year. I always save & quit before exiting, (unless there is a crash, which is very rare), and on this occasion I know I saved & quit as usual.
Don't know if it is at all relevant but since no one else has mentioned it, I'll just add that I saved & quit during a storm.
On reloading about 28 hours later, I had lost all penned farm animals, whether name-tagged or not, including axolotls (all named tagged), and a name-tagged cat. The first time I checked my nearby village it seemed to be deserted; I checked the nearest houses and they were empty.
I hurriedly saved & quit and reloaded, thinking I might be able to save some of the entities. On checking the village, there are fewer villagers but the ones who survived seemed to be further away from the place I was when I saved. My village is huge - I mean before the glitch it had about 50 villagers - and it sprawls over a large area. It's also very close to my house and therefore current spawn point. So I am thinking that the mods are disappearing within the chunk, or within a certain small number of chunks, of the current spawn point.
I have explored my world extensively and live about 2000 blocks away from spawn. I haven't yet gone to look for any of the other entities I had at other places in the world.
Hi Eric
My bees didn't despawn either. I thought that might be because I saved and quit in the middle of a storm and so they were inside the hives at the time.