[Freeswitch-users] Forbidden using UDP, works with TCP/TLS

Hi! I had a user registered using TLS transport. That was working fine but I want to change the ATA over to use UDP instead. All I thought I should have to do was to change the transport and ports used to register in the ATA (SPA3102). However, when I do this, FS responds with Forbidden. When I change the settings back to use TCP or TLS, registration is successful. What would cause FS to respond with forbidden? I do not change the username/password fields in either case. Thanks