iPhone 6s screen defect?

This might seem as a very minor problem but it does bug the minor OCD side of me. If you take a look of the photos I posted below, you can see that the screen protector on my phone does not stick on the edges. However, my girlfriend's phone has no issues with it. We both use the same exact brand of protector and we have tried 2 different brands and always no issue on hers. I have tried 3 separate protectors thinking that it might have been a defect on the protector but they all produce the same effect. All protectors are perfectly aligned. I have waited a few days to see if the non sticking part will stick but it does not.

Could this be a problem with the screen? Maybe the 3D touch mechanism is slightly bulging out?