For the records, we investigated for a customer the very same problem.

It turned out that 802.11r amendment makes Canon wireless detection go crazy and see WPA2 network as unencrypted.

Turning off 802.11r on Wi-Fi properties allows the printer to see the correctg encryption and connect.

After succesfull connection, by the way, you can even turn 802.11r back on if needed.

HTH, HAND.