I was hunting eggs to get Item tickets, then my game crashed when I opened of them. They disappeared after I came back. I have only one in my bank and the two I got recently disappeared from inventory.
I also noticed that sometimes, when I have x5 eggs, for example and use only one of them, the whole rest of eggs disappear. If log off and on, they came back. But seems that it's not the case here.
It's not hard to get them, but I don't feel like hunting then again for only a single weapon xD.