Hi,
Thanks for the feedback. I can confirm that COS and COR are set the same as other phones that do work. I will add though having checked the system. The phone is in a dept pickup group and a ring group plus a overflow ring group for the same dept. When an external call comes in the user is only transferring the call to another member of her team that would be in the same pickup/ring group. Could this have any effect on how the phone behaves?