@MojangSupport I have played a world with my friend and I had lots of progress, today once I joined the world I respawned at world spawn and lost my stuff I have tried to leave and rejoin which has previously worked now it doesn't this has happened to me since the end of 2021.

Oh no! Please make sure your friend has their world updated to the latest version and that your game is updated as well. If logging out and back in doesn't help, try restarting your game to see if that fixes it. ^AM

I have tried all of those options and none of them seem to work.