Caller ID for incoming calls?

Can someone explain why the Ooma mobile app can’t display incoming caller ID? After the call is answered the caller ID will show up. Is there some technical reason it cannot show the caller ID before I answer?

I have been having the same intermittent problem! It’s quite annoying.
Also, there is no way to really distinguish Ooma Office call from incoming personal calls.
I do hope this get eventually fixed!