From the pictures I see that you still have empty buttons on your phone.
I remember having this issue with Polycom, if you have, say 10 buttons on your phone, and you assign 5 buttons and then you add 5 to the EXP, it will fill up the phone instead of going to the EXP.
So try adding a couple more extensions to your EXP, and see if it adds at least 1 extension to the EXP.