I was in a Nether mine, among fire from beds on a friends world. I logged off out of fire, and safe. To join back on fire with 3 hearts. Afterwards all of my items despawned, I was also taken to world spawn after death, although my home bed was intact and untouched. When I got bavk the XP was still there, and my items weren't, this is an incredibly frustrating and upsetting bug to face, having lost almost everything due to weird spawn-ins