I logged off with a full inventory on a third party server. I saw an update to install java and I did, it went without a hitch. Then, I installed alpha 1.0.4 and played for a bit, then got off. After a bit, I went back onto 1.18.1 and the game acted like it was the first time I ever played it, with the multiplayer discretion screen showing. I logged onto the server, my inventory was gone and the tutorial popups were going.