Calls on iPad

I just got a new iPad Pro, and everything went seamlessly until I tried to use iPad to make calls from my iPhone. Here are the symptoms:

1. If I try to initiate the call from the iPad it says that the iPad and the iPhone need to be on the same wifi network, but they are.
2. If a call comes to me, I can answer it from the iPad, the caller can hear me, but I hear nothing. (The volume is up).

I appreciate any ideas.