Export policy enforcement for CIFS access has been disabled by default since about 8.2.
Check yours like this:
vserver cifs options show -fields -is-exportpolicy-enabled
If it shows false in the output, you need to enable it:
vserver cifs options modify -vserver <vserver name> -is-exportpolicy-enabled true
If this post resolved your issue, help others by selecting ACCEPT AS SOLUTION or adding a KUDO.