1. Sim should be slot 1
2. During login, Sim should be in the same slot as it was during registration
3. "Please insert Sim..." error occurs when user disallows phone and call access while registration. If it is occurring repeatedly, the user has to go to Settings>app>Ippb mobile banking > permissions > allow phone
4. Pls ensure all the permissions sought are provided by the user
5.Vivo > Messages > Settings > Verification Code Protection > OFF
6. If nothing works uninstall, reinstall