WIFI Calling Preferences Being Forced to Cellular Preferred

I continue to have the "Wi F calling preferences updated to optimize network experience" message appear on my Galaxy S9 constantly. It is changed from Wi-Fi to cellular, even though I have only one bar on cellular service and am 5 feet away from my ASUS RT-AC86U router. It seems like I miss calls when it is reset to cellular preferred.

I have many issues with this unwanted "service". If I set a preference, it is what I want and I expect my preference to be honored. Is this reset only on my phone, or is it also recognized by T-Mobile so if I get a call T-Mobile will only use cellular and not work if I don't have sufficient coverage?

T-Mobile has replaced my SIM card, but that didn;t help. There was a suggestion to clear the cache partition and reset network connection. I have done this repeatedly and it doesn't work.

It looks like I have three solutions: Take my Galaxy S9 to AT&T, stay with T-Mobile and replace my Samsung with a different manufacturer’s cell phone, or go to Spectrum/Verizon and get a new phone.

Note to T-Mobile: If you are monitoring this issue, please respond.