Access is denied. Failed to open storage error on CIFS shares from EMC data domain

[JasonPGTF]

My backup server actually has 2 repository mounted on it.
1 repository is a direct connect storage and presented on my backup server as a local drive.
1 repository is from a EMC data domain which I create a CIFS shares and mounted on my backup server as a network drive.

I notice that intermittently backups which kept data on my data domain will bump into the Access is denied error. The backups will, eventually complete successfully after the job perform retries.

May I know what did i configure incorrectly?

Error is as below
3/25/2021 11:15:04 PM :: Processing vm123 Error: Access is denied.
Failed to open storage for read/write access. Storage: [\\ddomain\veeambackup\vm123\vm123.vm-365D2021-03-25T231414_56BE.vib].
Agent failed to process method {Stg.OpenReadWrite}.

[foggy]

Hi Jason, please provide a support case ID for this issue, as requested when you click New Topic. Otherwise, your post will eventually be deleted by moderators.