I don't know why this bug is happening so I cannot give a concrete procedure 

But twice now I have loaded into my creative world and had my inventory/ player data not applied to me 

The first time my inventory was wiped and I was repositioned at worldspawn and the second time I spawned nearby to my original position but with an empty inventory 

Relogging appears to fix this issue however any items gained before relogging will be removed upon doing so

I have a few possible leads on this, namely the fact that my xbox account got disconnected at some point and that my world had been running for a few hours both times this happened, and that every time I leave the world it tells me that it failed to sync on the first attempt sorry I can't be more helpful I'll try to see if I actually recorded the clip so I can prove that it does did happen