Enter your CTU FTS e-mail as your nickname and eduroam password. Only username@fd.cvut.cz format is accepted. Don't use any shortened email as is surname@fd.cvut.cz.
And now try it again.
See us in the Horska Network Administration Office, create task in helpdesk or write us an e-mail describing the problem to eduroam@fd.cvut.cz.
We prefer to meet you in person as finding solution is usually faster and more successful when we have your device in hand.