Since todays restart/maintenance, the server is lagging more often now, and things seem to be "rolling back". In example, I have had to rebuild the same section of the area im working on 4 separate times. The same chunk going missing every 30 min or so. Other users have also reported items going back to their previous position in chat. Update: Less people are currently on, and have not noticed it happening within the last hour, but also noticed it seemed to happen when I would teleport away, and be gone just long enough for the chunk to unload.
I'm also experiencing this in VMR! I can provide screenshots and coordinates via PM if needed But where I had it happen it erased all my chests, and it happened right on a chunk border. You can see a clear cut from where I've been levelling things and I checked F3 to confirm it's on a chunk border.
Have not experienced any thus far. Have put down many many blocks and each time I continue on the build, every block is accounted for. I figured it had something to do with the way the chunks saved/unloaded, that was my first guess xD