I am trying to connect with my coach through the phone calling feature, but nothing is going through. I have the newest iOS 13 update.
If you are using iOS 13, and you are attempting to have a phone call with your coach, it might be suggested to save the phone calling number itself as a contact.
iOS 13 as a new feature allowing the users to block unwanted calls and this might prevent you from connecting with your coach,
Please read through this article for further information: This new iOS 13 feature stops strangers and spam callers from ringing your iPhone