It appears the uuid of the gameprofile appears to change after 6 hours or at least it's sending the server the wrong uuid after opening the game for 6 hours.
Issue: sends server(lan or possibly offline server) wrong uuid missing your crap on single player world this means your stuff get's wiped.
The only thing that should be authenticated fails after 6 hours is a token not your uuid you got cached into memory should remain the same once launched regardless whether or not it's authenticated.
If it's not changing then the issue is it's parsing the wrong uuid to begin with/downloading the wrong info.
Steps to reproduce:
leave game open for 6+hours
join a lan game
your inventory wipes your achievements are gone
if you are the host then it's permanently gone else restart the game and launcher then relog and it appears to have come back.
Side Note; uuid sends wrong info to the server in the first place sometimes even without the 6 hours this is probably a separate issue
Comments 3
yeah I think it's the verification system overeacting. If you ask me it should always use the same uuid. The verification itself should only be the username and pasword as maybe cross check if uuid matches mojang in order to be non cracked.
In a work around I set the uuid of the player on both client and server equal to the first time they logged in under the same username. Sadley name changes has a possibility of getting confused but, it's better then longing in and loosing your inventory.
I have been playing on a 1.13 multi-player server where the issue of items in player inventories go missing has happened several times. One player that is usually playing 6+ hours lost the entire inventory.