There is not enough info to really determine what the cause might be but I have seen this when people get their instances mixed up. Specifically they assign a role to a user in one site and then start a client or EP against another site where the user has not role.
Start a client against a specific AOS and go to System admin \ Setup \ Enterprise Portal \ Web sites and check that the URL’s point to the correct site and that the sites are working. If that is OK then your problem is not with EP or the role center as such.
Now go to the user that’s giving you trouble and make sure that user is assigned the role you want.
Open the EP URL you have in the web sites form and sign in as a different user, i.e. the one you are testing.
Repeat for each AOS instance and any users/roles giving you trouble.