Carina, your issue may be completely unrelated.
If your users keep getting the logon page again after authenticating..
I would start by verifying the role before and after authenticating. If it is the same, try and figure out why.
Can you see the authentication request in clearpass (Monitoring » Live Monitoring » Access Tracker)?
Under the summary tab, what service is being matched? What does it mention as Enforcement profiles? What is mentioned under the Alert tab?
If an enforcement profile was returned, look into this (Configuration » Enforcement » Profiles) and verify what is being returned. Is this the correct role? Does this role exist on the controller?