When OneDrive moves files to the Cloud Connected Backup throws out the error "An error occurred, please backup again or contact the Micro Focus Support.".
When in Windows Explorer the OneDrive Cloud File is downloaded, then Connected Backup is able to backup this file.
It would be a good idea then to have that all errors from OneDrive can be switched off and it shows that the Backup are successfully, because, when the files are in the OneDrive Cloud, there is no need for Connected Backup to backup it for itself.