AT&T WIFI calling not working with Xfi modem/router, calls don’t go through or fail outbound

I’ve tried going through some troubleshooting but there really isn’t anything specific to third party carrier WIFI calling failing? Do you have other info that would indicate the app can help Somewhat?

Are you able to provide a timestamp (date and time) where you have experienced this issue on your phone? 

I now have a timestamp ‘ ish when the wifi calling failed.. what can I do with that information?

@user_jjfogg, hello! Thank you for your comment. Can you try going into your internet settings on the Xfinity App and disabling Advanced Security? I would love to see if this make a different. 

I checked this setting on my xFi router and it’s not enabled… the xFI router is really only doing modem connection, and another AP connected to the xFi router via ethernet port is providing all wireless access, and to which all the phones are trying to do their wifi calling connections.  This has worked for 5+ years, but with a different Motorola modem and NOT the xFi modem/router combo.  Is there some other setting IF Advanced Secutiry is NOT enabled that could be causing this issue?

OK, that’s sound dubious but also somewhat implausible… I mean, it’s a protocol that should be transported and routed regardless of carrier.  Do you really think that WIFI calling from a carrier OTHER than Xfinity (I mean what if it was the PARENT of xFINITY mobile - VERIZON?) is being de-prioritized, depreciated to crippled just because one uses an xFI modem/router?