I have physical SIM newly put into a Pixel 3, and it is not auto triggering wifi calling when i am connected to my wifi. Or when I toggle airplane mode on then off.
I know when it is using Wifi calling as the phone, will say at the top Visible WiFi or T-Mobile Wifi for example. This works fine with my TM sin on the same phone as well as on my iPhone.
I can confirm the wifi calling is enabled and works, as putting the phone in Airplane mode and wifi on I can make and get calls and it says Visible wifi on it. And the settings in the phone are set to use wifi over mobile as preference.
Ive done that chat already, and i don't use Twitter or facebook.
ALl they had me do was the steps i already did, toggle airplane mode, confirm wifi calling is on, do a "network settings reset" etc. like i said, it works for sure when in airplane mode and wifi on. But only sometimes will auto engage after making normal transition when connecting to a wifi network. most of the time it does not auto activate.