My realm has had this issue since yesterday morning. I have seen this reported before but they're from around 2019 and resolved. So I am reporting it again as it's a big issue, because my realm is busy and I don't want this to go on too long and bore people from coming back.

This first came to my attention when I built something in my town, then I disconnect. I join back to see the save has reverted to how I joined and I lost all my progress on it. This was not too bothering as it was a small build but later it kept getting worse and disconnecting the players every 5 minutes or so.