Getting the same thing - cloudberry creates the files, then gets access denied to them. It is running as Local Sysetm Account, The files it is backing up are via a share with share credentials provided.
Explicitly giving SYSTEM full access... will see if that works.

So far, its a no go with SSHFS as the authentication on the SAN is not working... as in the share in on a SAN, but the authentication is controlled by a NIS server, so not sure how to work SSHFS in this case.
sshfs user@sanip:/share won't work because user is not a user on the SAN - users on the SAN are not allowed on the shares...

As the files are on a Linux file system, SMB is not applicable as far as I know.
I am working on the SSHFS now - will report on results. Thank you!

NOTE: Shares are mounted with fstab like :
10.0.0.5:/export/SANShare/Shared /SanName/Shared nfs hard,intr,nfsvers=3 0 0