Nikon d7100 not focusing correctly

Hello all,

Currently I have a Nikon D7100, noticed that it doesn't focus right, it shows it focuses but when reviewing the final result there is a blurriness to the faces/subjects.

I tried.. using multiple lenses even one that is not Nikon, manual and automatic focus, all focus modes on the camera, factory reset, only shooting in jpeg.

As for the camera itself I noticed the lock mirror for cleaning option on the menu is greyed out so I assume it's something wrong with he sensor?

Thanks! Appreciate your time.