Looks like the only solution is to go abroad. I can't get 5g working in Ireland yet I am roaming in Poland at the moment and my Pixel 8 pro connected to the 5g network without any issue, even it's not officially supported by 48 network while roaming....
Seems to be a Pixel issue. I have Pixel 8 pro and can't connect to 5g either. I've contacted Google support and they told me that 48 is not supporting Pixel phones that's why I can't connect XDddd
