I started a new world about a month ago and i noticed that even though i have 250+ days played (I can see this with f3) in Statistics it says i only have a few hours of play time. Also it says in Statistics that i killed only like a hundred of zombies when i know for a fact that i killed thousands in my exp zombie grinder.

And about the advancments are also a real issue, i got my "Take Aim" advancment three times by now as well as "A Seedy Place", "Glow and Behold!", "Best Friends Forever", "The Parrots and the Bats" and "Monster Hunter" advancments. Its a real issue for someone like me who is an advancment hunter and likes to have them all done.

I dont have any actual proof of all of this but i could probably get it in a week or two if needed.

I just realised that i have proof of the stats being deleted, in attachments below youll see a screenshot of f3 in my world and a screenshot of stats, look at days passed in f3 and time with world open in the stats screenshot, it says that ive played for 261 days in f3 and it says ive had the world open for 1.25d in stats. One day without the night is 10 minutes, so that means ((261x10)%60)%24 is about 1.81d of irl time(not including the nights i havent slept), it doesnt match the stats time.