I first experienced this when playing in Minecraft Realms. I was working on making a turtle exhibit, and had about 7 eggs in it. I had been waiting multiple days for them to hatch, and I was confused to find out that multiple of them had disappeared. At first I thought that my friends were destroying them, but I soon realized that it wasn't the case. They continued breaking and disappearing, so I thought mobs were spawning in and destroying them. That still wasn't the case. I looked it up and saw that many others were having the same issue.