Domain Users & Domain Administrators groups

Another issue surrounding groups - they are not dynamic!  I’ve added users to the group memberships on Active Directory and the WD NAS does not pick up the new membership.  Every time I add a new user to my environment with appropriate group memberships, I must remove the groups from the authorized list on the NAS and re-add.  Then that breaks other people from connecting.  Is this a problem with Samba?  I ended up just giving public full access to everyone and I am hoping no one at my company messes up the files.