I started a new world and build an egg farm. Floor is 4x4 of hoppers, walls are 2 blocks high, and I threw in about 20 chickens.
It seems almost every time I return from the Nether, the chickens have glitched out of the egg farm and are running around the yard. It also happens occasionally when I "Save & Quit" then return to my world.
I think this might be a similar issue as with the zombie villagers described above.
Working in a new world, I dug a hole (2x2x2) and rode 2 trained horses into that hole so they would be available later. When I went into my world a couple days ago, the horses were just gone (saddle and armor also.) Just mentioning as maybe it is related.
I had a 12 villager farm house I used for trading carrots.
100 blocks away, I had an iron golem farm with 20 villagers. (All librarians with great trades.)
When I logged in last night, all villagers from both locations, GONE! From both locations.
Playing on Xbox. Not going back again for a while. Very frustrating.