You don't read. You respond too quickly. The mobile operator doesn't want to help me. They think it's not important. The fact is, with the same GSM card on version 16, there's no option to choose 2G and 3G. After reverting to 15.7, everything came back. Yes, I managed to revert the iPhone back. I lost more than 7 days researching and trying to revert it. If it says it can't be reverted to a signed version, it doesn't mean it's 100% accurate. It can be done, there are ways.
There is 2G here. Old super stong network . They haven't announced its shutdown. There is no 5G. 2G works for me in extremely enclosed spaces such as basements and warehouses made of metal. That. That 900Mhz frequency can pass through. The problem is when the phone persistently tries to switch to a 4G network, which is weak at that moment. It's silly that they removed the possibility to manualy choose the network you want .
Here’s another interesting detail about privacy: On a 2G network, it's not as easy to track you, plus the internet is ultra-slow