It seems that the possibility to call from Contacts app is partially broken in beta 2.
(I have seen the situation with SpeakerBox sample app also)
It is possible to call from Contacts if you have already done a call from app (or if you add an entry with your app name in a contact)
However if you press on the call button, I don't see anymore the list of all CallKit enabled apps (starting with iphone, facetime) in the action sheet.
Have you seen also this change ?