The most likely cause of the problem is that EAP-TLS is not checked in the Allowed Protocols list. Since the logs indicate an EAP failure and EAP-TLS is a common protocol used for certificate-based authentication, not having it checked would prevent wireless certificate authentications from succeeding.
The NAC Agent uses UDP port 8905 to send discovery packets to an ISE Policy Service Node. This is because the Network Admission Control (NAC) uses the SWISS protocol, which is stateless and operates over the User Datagram Protocol (UDP).
