Yesterday I was playing on my realm with three other people. We all got kicked at once and after struggling to rejoin, when we finally did the world was as it had been about 10 or 20 minutes prior. This happened again later in the afternoon, however no one was online. I left the game and when I came back later the world had been setback again. I am the owner of this realm so I know that it wasn't reset to a backup.
This happened before in probably June or July but it was about an hour of progress setback. The instance in July happened in the same manner that the second time yesterday happened; no one was on and when I went back online my progress hadn't been saved.
Note that I am using fabric loader with optifabric, minihud, and litematica installed but other people that are playing vanilla had the same issue at the same time yesterday
Linked issues
Comments

yeah i was using fabric but other people weren't and they still had the same issue and i've had this issue before when i wasn't using fabric
In that case, does REALMS-4218 happen to describe your issue?
This actually appears to be a duplicate of REALMS-4224 which hasn't yet been resolved. If you have any additional information to provide regarding this issue, feel free to comment on the parent ticket. If you feel that this issue is affecting you, feel free to vote for the duplicated ticket, to give Mojang a basic idea of how many people are impacted by the problem. Just to further inform you, this will not determine how quickly the bug gets handled or fixed.
Hey there!
This report is invalid as a modified game / launcher has been used. In this report, you stated you were using "fabric" when this problem occurred and this modification is not support by Mojang. To add on, the bug tracker only handles issue relating with unmodified game versions (vanilla Minecraft).