'important carrier message unlock iphone to view message'
I just wanted to post the solution to this problem - ISSUE
The SOLUTION is below:
If anyone is facing this issue. This is the below fix.
Go to Mobile Service > Sim Application > FLASH! - (A menu will open) > Click "Activation" - (Another menu opens) > Deactivate > You will get a new flash message, just do what it says to deactivate.
`iOS version 17.6.1 | Sim Carrier Vi | Country India`
This thing is called FLASH messages. For some ungodly reason, in iOS this option is enabled by default for carriers to send ads. In android, its automatically OFF, but can be turned ON.
PS - I have mentioned the version and my carrier. The steps will be same for all carriers. The name could be different in menu settings, etc.