Unable to make a call from another device after enabling "Allow Calls on Other Devices"
I have an iPhone 13 and an iPhone XR. The iPhone 13 has a SIM in it but the iPhone XR does not. Both phones are signed into the same iCloud account. With this setup, when I call my iPhone 13, the call is successfully relayed to the iPhone XR, so this is fine. But when I try to make an outgoing from the iPhone XR, I immediately get a 'Call failed' message on my iPhone XR. So why isn't this working ? I thought making calls from 'other devices' is also supported. Is this not the case ?