Metadata inconsistent and Sync Error (Access Denied) - Windows Server 2022 to QNAP NAS

I am experiencing a persistent “Access Denied” error during the final metadata synchronization phase of a file backup. The backup successfully hashes and transfers the data, but fails at the very end when trying to sync metadata/permissions to the target. I also noticed that the backup succesfully register on the NAS and Urbackup but sends back the error message on the Logs.

UrBackup Server OS: Windows Server 2022

Storage Target: QNAP NAS via SMB/CIFS Share.

I have tried to

  1. Verified the target folder on the QNAP has Advanced ACLs (Windows Permissions) enabled.

  2. Ensured the service account has Full Control over the share and all subfolders.

  3. Forced permission inheritance across all child objects.

  4. The error persists specifically on the “Metadata” step at the end of the backup job. Any suggestiosn to the solution?