Small blue line when using camera of iPhone

When I’m opening my camera there is one small ‘ like blue line coming and when I am zooming the ‘ sign is getting bigger and again after zooming out it’s getting small ‘. Can anyone suggest what to do as I have already cleaned my lens and updated my software also restarted my phone but the issue persists. I have attached the picture and marked it in yellow.

[Re-Titled by Moderator]