All items lost upon death

Whenever I die (no keep inventory) Sometimes my stuff drops and sometimes it doesn't. I was in a survival world (3 players) and my friend killed me. And when I come back to get my stuff, it's not there. maybe it had to do with the number of entities nearby (we had a chicken farm next to us) But I'm not certain.

UPDATE: I haven't experienced this problem again so it may have been fixed.