Facing proximity sensor issue on iPhone 12 with IOS 14.7.1

Purchased an iPhone 12 Purple a couple of days back and installed an edge-to-edge screen protector on it. Recently I noticed weird proximity sensor issues when I used the phone for the first time after unlocking.

After dialing a number, the screen would turn off after bringing it near to the ear which is expected. But it won't turn on the screen even after moving away from the ear, and I'll have to double click the power button to wake up the screen. As I mentioned already, this happens mostly when I used the phone for the first time for calls after unlocking the lock screen.

I'm facing this issue 3 out of 10 times a day and it's very much annoying. Tried removing screen protector and back case but that didn't help either. Tried restarting the device too...

Since this is not happening all the time, Could it be a software issue?