domain groups not allowing folder access for some users

recently we performed a permissions change on a server that was using local groups to provide permissions and created domain groups to provide access, after this change several of the users that are in the new groups complain that they are unable to access files, share permissions were set to read/change for users and have not been modified. Any test account is working correctly and effective permissions show that the users have access to the files but when they try to connect they get access denied. Adding them explicitly to the ACL allows folder access. I’ve checked just about everything I know to check when dealing with folder permissions but they all look correct, is there anything I could be missing?