Wifi calling on Pixel 2 resets to "Mobile preferred" even after setting "Wifi Preferred"

[markgmidei]

Does anyone have a simple solution?  I need to use WIFI callin in my home, where I have a good internet signal, but terrible mobile coverage.  I set the roaming preference to "Wifi preferred", but the WIFI calling preference remains "Mobile preferred".  The phone will try to use the weak mobile signal, resulting in a poor quality call.

In advance, please do not suggest 1) reverting to airplane mode, or 2) buying a range extender.

This seems to happen for a few months after every system update.