Pets with name tags despawning

I have a horse, donkey and a mule that are always enclosed in a fenced area, also a pet parrot. I was riding a donkey and had to save and quit, i joined back to find my parrot, donkey and horse despawned (all were saddled and nametagged, except for the parrot.). All i had was my mule, after leaving and rejoining soon the same happened to my mule. (MCPE)

I lost 3 saddles and diamond horse armor, and want them back :/