Wi-Fi calling not working on iPhone 11.

I can’t get wifi calling to work on my iPhone 11. I’ve updated software to the latest iOS, re-cycled my phone, turned wifi calling off and on again, reset my network settings—the whole kit and caboodle. Still nadda. It keeps telling me that there is no network connection and to turn my phone out of airplane mode or connect to wifi. I am connected to wifi. In fact, I’m posting this question using my phone on that wifi network. Others are able to use wifi calling/sms texting on this same wifi network, yet not me. And my carrier supports wifi calling. Any tips or tricks? I’m about at the end of my rope. This is the second wifi network I’ve tried and zip. I’m out of country and am trying my hardest to not take my phone out of airplane mode. Do I need to switch airplane mode off and on again for wifi calling to work? Any advice please! I am expecting a phone call from my doctor tomorrow and would very much like to just use wifi calling. TIA.