Bedrock Realm keeps reverting

Many times over the last 2 days, I have left my realm after several hours work, only to return to it in a previous state.

 

Restoring backups is not a solution, as they don't seem to have my changes in either, it's totally as though the realm is not saving changes as it goes, so the backups don't have the changes either.

 

As you can imagine, this makes using one of your expensive realms pretty pointless.