Are you using your home institution Eduroam or IAS Eduroam?
If you are using your home institution Eduroam, check your credentials. If you are still having issues, please contact your home institution for assistance. Perhaps there is a problem with their authentication system.
If you are using IAS Eduroam, did you install the CAT tool?
Visit https://www.ias.edu/wireless-user-guide and download the CAT tool
I already have the CAT tool installed and it is still not working. What do I do?
Try removing the Eduroam profile and reinstalling it: https://commons.lbl.gov/display/itfaq/Remove+eduroam+Certificate
It is still not working. Now what?
Please check your DNS settings and remove any external DNS servers you have configured. Please write them down before you delete them, as you may need to put them back once you return to your home institution.