wifi calling in Pixel 4a 5g, I can't hear

I have Pixel 4a 5G and am having exactly the same issues. When I am calling someone they can hear me, but I can't hear them. If I am calling 611 I can see that call started, but I can't hear even TMobile greetings. I have called TMobile multiple times on this and they tried to replace SIM card, to set LTE as preferred network instead of 5G, eventually even replaced my phone, nothing helps. The only thing helps is turning off WiFi (at lest it helped couple times) but that is not an option. Most of the time I have to reboot the phone to fix it. This is becoming really frustrating, because I am missing important calls, I can't rely on this phone anymore. Considering to go back to my Pixel 2XL (which has newer ever had any such issues). TMobile/Google have to fix their stuff.