WIFI Calling Preferences Being Forced to Cellular Preferred

It seems to me that many are having this identical problem… those of us who depend on wi-fi connectivity because we live in a hi-rise building or in an area with poor cell coverage. These wi-fi connectivity issues began with a system update in mid-2020. If you select "wi-fi preferred" within a short period of time your phone will revert to "cellular preferred". T-mobile has given me different phones and the same thing happens on all of them.  Worse yet, I have had multiple instances of an incoming call -- when on a wi-fi system -- going directly to voice mail and my cell phone never rings. I have observed this issue myself by calling my cell phone from a landline phone. I have tried temporarily deleting various apps from my phone -- but the same issue persists. This is not, I think, from my phone, my apps, or the wi-fi network I am on. It seems to be a software issue. Complaints are coming from Android and Apple users which are similar. Should not T-Mobile get this technically resolved? And would it not be honest to send out a blanket announcement to T-Mobile customers that "wi-fi is not working properly and we are working on it" or something like that? It seems to me that it is not fair or honest to advertise a service which is not properly working. Or openly solicit any problems we are having with T-Mobile wi-fi connectivity. I really love T-Mobile availability most places in the world -- buy the wi-fi connectivity is a big issue for me.