Terry Meme
Comments
UPDATE: Chests that have been STACKED cannot be placed on donkeys or mules (haven't tested Llamas), however a freshly crafted non-stacked chest was able to be placed!
I have both a donkey and mule and neither have a chest slot when riding, Along with the other donkeys I've had in other playthroughs. I know the health, speed and jump height do differ and can be bred into other horses and the such.
Either way I'm fairly certain it's bugged for survival, I can place a chest on the mule/donkey no problem in creative
That is possible that the stack didn't work due to being from an older release (one right before aquatic phase 1) though I remember attempting to place a chest that naturally generated (blacksmith chest from village) and that didn't allow me to place it on the donkey/mule.
The world was created about the same time (before phase 1), in the Bedrock version and not transferred from the Xbox one edition.