SMB Permissions on a Windows AD Domain Joined NAS

Hello all,

Can anyone guide me with the folder permissions issue when adding a security group from AD on the folder in NAS, users inside that SG cannot access the folder, but if I select the default “domain users” it works, or the user individually it works too.
My English is not perfect I hope my issue is clear


Normally when I see issues like this it is due to the fact that somewhere along the way you have explicitly stated ‘no access’ to the domain users group to that shared folder.

A ‘no access’ permission on Synology will override a ‘read write’ access.

No, on the domain section, I even tried to give permissions to that security group on all apps and read/write on all directories as a test and also it did not work!
Works perfectly on users selected individually or on default Windows Security Groups such as domain admins or domain users