Sorry, missed that in your other post. As far as I understand it, the SMS messaging has nothing to do with the Wi-Fi calling feature. Totally separate. I’ve never had a problem SMS messaging on most hotel WiFi’s...but sometimes the wifi signal simply doesn’t trigger the “W-Fi” indicator in the upper left of the phone’s home screen...either because the wi-if just sucks, or because the country I’m in may not have a drug deal with AT&T.
I just leave the Wi-Fi calling ON in the Settings for the phone...and take what I can get when I’m on the road. But that Wi-Fi setting doesn’t change anything with my phone bill...it just occasionally allows me to use the phone normally (as if I was in CONUS with a cell signal) when I’m cooped up on hotel wi-fi somewhere. Might be worth noting that when I’m in CONUS with ****ty cell signal, this wifi calling feature has allowed my phone to still make normal calls. So it’s not just limited to overseas.