Problem with files missing

out user have nextcloud server, there they have installed group folder app. After auto update, sync between server and their desktop app stop working, I resolved it with veem backup files to the state before update and it started working. Now, the problem is that files, which were created between server not working and server working again, are deleted from users computers and I wounder why and if they can be somehow retrieved.

Best regards

If you restore from backup, there is a step where you can create new fingerprints for the files. This way there will be a conflict for changed files and a copy is kept ( In your case, this is a bit too late. The easiest would be if you have a client that wasn’t connected and that still has this altered version.