Can't receive FaceTime calls on iPad Air 2
iPad Air 2, iPadOS 15.7.1, iPhone 8 iOS 15.6.1. My wife uses this iPad weekly and gets/receives FaceTime calls from multiple sources. Today she could receive a FaceTime call via cellular on her iPhone but it would not show up on her iPad. Note she does not have cellular on the iPad but does have "Calls from iPhone" ENABLED on the iPad. I have confirmed we have both devices on the same WiFi network and logged in correctly.
I have found that I can call her on the iPad if I use her me.com address but not if I use her cellular address. Frankly we've been gone for a month and we've not used the iPad -- so the settings haven't been changed. I'm really flummoxed about this.
Would appreciate any thoughts about what could have changed, and how to restore the service.