Hi, this happened to me 2 times already, corrupting my file and have to start all over.
I noticed that it only happens in the Nether when you stay in it for a long time. It starts by stopping the map loading, then not being able to use some features (Curios Inventory / Backpack / Occultism Remote Storage). Then, when you try to quit the game, the "Saving World" screen remains indefinitely. We can only leave Minecraft with the menu Ctrl + Alt + Delete.
I think it's a pity that after more than 20 hours of play, my game becomes inaccessible twice in a row.
Thanks in advance.