I have 2 apps in active state and 2 registered phone numbers, right now both apps are associated to the same phone number, so I just want to change phone number in one app, i.e. let's call my apps A and B, and phone numbers 1 and 2, the situation now is:

A -> 1 B -> 1

but I want this:

A -> 1 B -> 2

When I go to the API configuration section in control panel of app B I see both phone numbers in the dropdown list, I can select phone 2 without any error and it remains selected, but when I leave that page and come back later the phone number is still 1. Am I missing something or is it really a bug in the control panel?