Hi igor, we have apps running in V3, didnt notice such behavior.
I think to:
1) delete the old local db, make a new one -> restore locally ->modify content ->backup, try restore in cloud & and create a 2nd new local db based on this backup to see whether is running locally
2) if not, i would file a ticket to mendix about this cloud issue, may they know more
3) if modications are urgent, i would build in the logic/interface to modify in the cloud...if it is a cloud issue by mx, it would take time.
Maybe it's a version mismatch? Check that your version of Postgres locally matches the one in the cloud. You can see the exact version running in the cloud by starting your app and watching the logs.
Are you on the V4 cloud? I had this also last week but had not time to do a support request and I could work around the issue. So file a support request because there might be some bug in the V4 cloud in doing the restore.
Regards,
Ronald