1. Open the Settings app.
2. Tap Mobile Data
3. Tap Mobile Data Options.
4. Turn Data Roaming ON.
5. Turn Voice & Data to 4G or LTE, not 5G.
6. Press the Back arrow to save changes.
7. Tap Mobile Data Network.
8. Under Mobile Data section and under personal hotspot section, check if there is an APN named cablenet.
If not, enter the following:
        - APN: cablenet
        - Username: (leave blank)
        - Password: (leave blank)
9. Press the Back arrow to save changes.
10. Tap SIM Applications.
11. Then tap Roaming > Select Mode > Automatic.
12. Restart your iPhone and test the connection.

По этой инструкции все сделал и заработало.

Здравствуйте! Решили как-то проблему?
Тоже не ловит сеть в рф

Смс коды нужны :(