Random entities despawning within a chunk

I’d spent most of my day getting diamond armour and a cat, i left the game for a few hours and found that both my cat and the armour stand that was holding full diamond armour had both despawned. Everything else was still there but after reloading the game they were still gone. The game was not on multiplayer mode, i also checked the nether to see if my cat was in there but i couldn’t see it. The cat and the armour stand were on the same row of blocks.

(me and my cat) (his name was marmalade)

(it could also be a texture pack issue but i think because just certain entities despawned it’s a bug)