iPhone 5s LCD/Digitizer Pressure Fade Marks after Screen Replacement.

Hello, a few days ago I replaced my iPhone 5s screen. The installation went very smoothly and afterwards, everything looked and functioned like new again. Then, just after 2 days of light use, I noticed large white / gray patches on the majority of my screen, except for the edges. The more I paid attention to it, I noticed that the pressure my fingers were placing on the screen was causing either the LCD / Digitizer or back light to create this large gray blob. The blob eventually disappears in areas of the screen that haven't been swiped across in awhile.

I have noticed a few other people describing this same problem, and some answers offered up are that its common in after-market screens, and also that it could be due to battery either bulging or not having enough adhesive between it and the screen, making it so that the screen depresses some, thus leaving a mark. I don't think the battery is the issue; I didn't touch it during the screen installation, and there was no adhesive to be applied in that area, as far as I could tell.

This youtube shows the problem really well:

https://www.youtube.com/watch?v=RGKA3gOQ...

And this photo:

https://i1184.photobucket.com/albums/z33...

Anyone know what is most likely going on? The after-market screen that I bought was not one of the cheapest and received perfect reviews on Amazon..

Also, I noticed some icons were leaving burn-in marks that quickly fade away when pressure is released. Not sure if this is related..

Thanks in advance.