I've been playing Minecraft again for the last few days-

I leashed a bunch of 5 sheep on fences so I'd be able to make a den for them when I have the materials, I leashed a horse (though it already has a saddle), I kept 2 dogs and took care of them until they multiplied to about 8- and I leashed 2 goats in a newly-built den.

At some point, I got some diamond armor for my horse, and yeah- it was nice and all.
Until one day, when I logged back in, it unfortunately suddenly disappeared. When I checked, the knot of the leash was still on the fence. This made me wonder- so I killed one of my sheep that was leashed onto a fence, but instead of the leash's knot staying there, it unknotted; to conclude, what happened to my horse was definitely 'unnatural'.

I thought maybe this is a loading problem. So, I left the world, came back, and it still wasn't there; then I walked 200 blocks away, came back and it still didn't load in. I looked this issue up, and it's existed for awhile- some sources mentioned what I did, and others said there was no fix for it. So, I just accepted my horse's fate, and got a new one (there was another leashed horse in a village 800+ blocks away, and it was still there, if that info helps.). This time, I learned that maybe I shouldn't keep the diamond armor on the horse in case the same thing happens to him again. In my mind, maybe it wasn't even a bug- maybe he did die, and the 'leash being unknotted' was simply a thing that happened to players only- or maybe it really was a bug. I digressed- there was nothing I could do or could've done.

Then at some point, I got to trap 3 zombie villagers, and it took me about an hour to get everything I needed to cure them, and I successfully did.

But again, when I logged out and logged back in a few hours later- they were gone. But not only that, my sheep were gone, my goats were gone, and to my dismay, even the horse and dogs (not the dogs!) were gone. My heart dropped for a second realizing that my beloved-ass villagers went to Aether- or the void, in this case. This time, the leash's knots weren't there anymore. So in the end, what I did for those zombie villagers felt pointless. But on the bright side, I was right about the horse- and I got to trade some good deals with the villagers before they got Thanos-snapped. (If it helps; I sometimes go on peaceful mode, but even then, none of the mobs disappear. Even the already-cured zombie villagers (and also, this all happened in the span of 3 days.).)

It did take me awhile to keep these lovely creatures, but again- there's not much I could do about it. I really come to Minecraft to take care and build homes for them, but if this bug still persists, then it's going to be very lonely and less fun. I might stay off for a bit before I come back. I think next time, I'll log out somewhere far away. If the horse in the village stayed even after the disappearance of my last horse, then maybe the same would happen to my creatures.

I hope this helps for fixing any kind of bug on the loose. If this is a bug that goes on for other players and something you have to fix- take your time, and I wish you all the best.

Thank you! <3