You used to be able to use the ##4636## trick to get a hidden menu, but now that’s gone too. There’s nothing in the menu that alllows you to select which network to use. I hate to keep having network disconnects and in perpetual 4G/5G back and forth and battery draining.
I use Samsung btw
Edit: For context: Its due to issues with being near the edge of the 5G zone so your phone keeps going back and forth between 4G and 5G which (I suspect), is what causes constant network disconnection, phone being hot/warm, and battery drain. Very annoying.
It’s a carrier thing, you can disable 5g on Samsung phones aswell but for some reason they let the carrier force it
From the perspective of a whitelist firewall as your ultimate right to internet privacy, the inability to run all of your internet traffic through a select device is a major violation of privacy on par with forcibly removing the front door from one’s home IMO.