Everytime I start up minecraft, enter my single player world, and do a task I had done previously, like picking up diamonds, I would get the advancement again.
I looked into my saves folder and I have ten json files in the advancements folder. Same for my stats folder.
Is this supposed to happen? Is it because I'm not using a paid Mojang account?
I'm playing 1.12.2 with Forge, Optifine, Aether, Twilight Forest, Biomes O' Plenty installed.