Thanks for the reply. It is a new extension, so there are 3 CA's, no forwarding, no DND. Monitor reports the station as busy when you try to call it. System status says the phone is ready, but when watching it being called in active calls, it never shows it trying to ring that extension.
Going to try deleting that extension and rebuilding it. Maybe something messed up when the SIP station was created. Have seen that with regular IP stations before. I will post the outcome.