Wi-Fi Calling on iCloud-connected devices not working

[sdsvtdriver]

I have two iPhones - one on ATT (home) and one on VZW (Work). I cannot get home iPhone to ring when work iPhone is called (and vice versa) except when they're both on the same WiFi network. Both devices use the same Apple ID and are signed into the same iCloud account, both have WiFi calling turned on and calls on other devices turned on. Home iPhone appears in the list of device on work iPhone and vice versa.

According to https://support.apple.com/en-us/HT204039, both carriers support calling on iCloud connected devices.

There's not a lot of troubleshooting steps to take online. Most are regarding iPad to iPhone, Mac to iPhone, etc. Has anyone else have this issue and solved it? I hate carrying two phone everywhere.

thanks.

 

[chscag]

I wouldn't expect it to work except when both are on the same WiFi network. Otherwise they both would have to have the same number.

 

[sdsvtdriver]

Why is that? an iPad can make & receive a call via an iPhone that is not on he same wifi network.