I am with Three mobile. I have tried to put the sim in my old phone and works perfectly fine. I did try doing airplane mode for 5-10 seconds doing on and off. My network will show up but after 5-10 seconds it will turn off or couldnt get any signal even going outside the house is a struggle getting a signal.
Phone has been updated to latest version.
Build number - ww_33.0820.0810.232
Hello, this happens in Slot number 1. I can confirm all connections are enabled for 2,3,4G and 5G network.
I had no issues when I was in Denmark, in fact I got a much better signal than in the UK.