Problem phenomenon:
If the parameters are incorrect after manually modifying the APN, the Internet may not be available.
Solution:
After resetting the default APN configuration, you can surf the Internet normally.
realme UI 3.0 and above versions: Settings > Mobile network > Select network card > Access point name > Three dots in the upper right corner > Reset access points.
realme UI 2.0 & 1.0: Settings > SIM card & mobile data > Select network card > Access point name > 2 dots in the upper right corner > Reset access points.
realme UI R & Go & S & T & U Edition: Settings > Network & internet > Mobile network > Select network card > Access Point Names > 3 dots in the upper right corner > Reset to default.