While mining in Realms I have had 3 tools vanish on me. One was equipped and in use, the others were just in my inventory.
The one that was in use was a Diamond Pickaxe, enchanted with Unbreaking III, Silk Touch I, and Efficiency IV, if that matters. It went from a working pickaxe to a stack of 28 Wheat right before my eyes. It was brand new, maybe 40 blocks mined. The other two were an enchanted Diamond Pickaxe (Fortune III) and a Shovel (Silk Touch I, Unbreaking III, Efficiency III)
This seems to be just with the new 0.16.0 recent client. I do not plan locally on my phone, just on Realms.
I had this bug hit me last night. I had 3 picks disappear off my 3rd hotbar slot.
A friend and I were playing at the time. and he was breeding sheep approx. 100 blocks away. And I was sorting out inventory into chests.
The first pick was replaced with 56 wheat. which was funny because I had no wheat in my inventory and neither of the chests I had opened had it either. So I put another pick in that slot and placed the extra wheat into a chest and continued to look for the first pick thinking I mistakenly placed it some where. During this time that 2nd pick disappeared and another stack of wheat appeared! This time it was 54 wheat.
Hmm, Thinking this can't be right, I must have done something stupid, so I placed another pick into the slot and began to to search for the missing picks, opening chests, stoves, and any container I opened since the first disappearance.
And then the 3rd pick I put in the same hotbar slot disappeared with what? A stack of 52 wheat!
So I got suspicious and tried to test this out. was it the pick or the slot it was in. So I went to the zombie spawner that also was about 100 blocks away from my sheep breeding friend and began to kill zombies. This time I put a rotten flesh in that slot and began to accrue zombie drops. during this time the rotten flesh in hotbar slot 3 disappeared and a stack of 50 wheat replaced it. It was then that I asked my friend what he was doing during this time and he said he was breeding sheep and he was down to only 50 wheat.