Files not visible with AFP but with CIFS

Have you checked the configuration under Shares > Share Listing > Sharename > CIFS and Shares > Share Listing > Sharename > AFP in Frontview for a possible explanation.

I'm not sure what configuration you mean but maybe I have to clarify what the problem is:

I have a share with several folders. This share is accessible from both, CIFS and AFP. But one folder in this share is shown as empty if I access via AFP. But if I access this folder via CIFS, the files are shown.

Is it possible the extended attributes for the files are set making the files hidden to Finder? These would likely remain intact via an AFP share, but be ignored, hidden or stripped via an SMB/CIFS share. Do you know how to check with Terminal and xattr commands?

ls -l
- "This will list files in the folder. If there is an '@' after the permissions, there are hidden attributes. If so....

xattr -l filename
- "This will show you the extended attributes"

Might be way off, but I've has similar issues and this is typically the issue.

I'm not familiar with the file structure on the NAS but I try to check this on the weekend. Thanks!

Is there any way to check this via front view or the reassign the mandatory rights via front view?

If you go to the share listing from the admin page and click on CIFS (or any other protocol), you'll an advanced option tab on the far right. This has an "Advanced Share Permission" section that lets you set the owner, group, and owner/group/guest access rights for all files in the share. Check the control next to "Set ownership and permission for existing files and folders in this share to the above settings. This option is useful in cases where you are changing security levels and need to workaround file access problems." Then press the apply button at the bottom.

The permissions are reset in the background, if you stay in frontview a dialog will popup telling you that is it done.