@MojangSupport I just played for 3 hours with my friend, we logged back on to find the save file reverted to an older save.

Are you updated to the latest version and have you checked for a backup? Also, if you let us know what Edition you are playing and what kind of device, we can try and investigate further! ^AM

Yes! So we were playing the PlayStation 4 version on our PlayStation 5, we both have the game to its current update, and I tried looking for a backup on my PlayStation plus, and I redownloaded the backup save to my system but it just loaded the reverted save

Hmmm, when exiting, make sure the chest icon (that indicates the game is saving) is not still hanging around. Also make sure your PlayStation account is connected to the internet. If this issue persists, let us know though so we can get you to the Tech team for a deeper dive. ^AM

Will do, Thank you for the help!

I did exactly those steps and the save reverted again.