Why doesn't my iPhone 6 refurbished replacement screen sit flush?

Hey guys,

I recently replaced my iPhone 6 screen with a refurbished display from Easyphix, and after switching over the components from the old screen to the new one and installing the new screen, I noticed that while the top of the screen fit properly, the rest of the screen was slightly lifted up from the phone chassis [See image here or below - https://imgur.com/a/zRpb8ut ]. (The gap on the right is ~1mm wide and properly depresses when I press down on it so I don’t think its due to a blockage of some kind. Perhaps faulty screen clips?)

I should also note that with the old screen, I cant tell whether that has the same issue since it has so many cracks make parts of it not sit flush anyway.

I've tried fixing the slight bend in the phone but that didn't help. I've also made sure all screws are screwed in well.

The only solution I've found to a similar problem was to replace the battery due to potential swelling, however looking at the battery, it appears completely flat so don't think that's the problem.

Any ideas, and suggestions will be greatly appreciated.