Despain Minecraft Sheep?

ch
4

I now have about 50-60 sheep in the enclosure with the white ones. But it looks like it's only 20-30, which I think so too. Does anyone know why this is? Despavnen perhaps the sheep, if too many are on a certain large area, or why is it?
Here's another picture

Vi

It may be that these were despawnt because there were too many in a chunk or because the chunks were not loaded and they are despawnt because you were out of reach

ch

Is there an indication of how many may be in a chunk?

ch

Besides, my enclosure was no bigger than a chunk, probably because of that, right?

Vi

I just looked and there's nothing to be found about a superset. But I have heard that there's one.