Why is my infinix note 3 pro displaying a circular icon on the top left corner of the screen?

[Chapmax]

Since I upgraded my phone from Android 6.0 to 7.0 my phone displays "no service" and the circular icon has been up after the upgrade. Does the icon have anything to do with the "no service" problem?

 

[B. Diddy]

Welcome to Android Central! Show us a screenshot of what you mean: https://forums.androidcentral.com/g...ide-how-post-screenshots-android-central.html

Was the upgrade an official one pushed over-the-air, or obtained fromm the manufacturer's website?