What is this battery backup,so bad after last security update, it's terrible 

When verifying mobile number for payment apps in Secure Folder,it's showing unable to Send Message. I'm not able to verify

Everything was working fine , but suddenly My network showing No Service in Sim Slot 1. I tried flight mode, reset settings, restart phone. Nothing really works. Then Switch Sim to Slot 2 Network showing. Slot 1 is not showing network, without any re...