Bumper not flush with fender

[Jtph00]

I installed a front splitter recently and it's pushing against the edge of my fender lining, creating a gap between my bumper and fender. I don't want to make changes to the splitter because it's currently sitting flush with my nismo bumper just how I want it to. I figured the fender screws should solve the issue easily but for some reason, it's not clamping it together. It feels stripped when I try to tighten it completely down but it still catches and goes in fine initially on both sides.

Although latches would be cool, I rather not drill holes on my bumper for now. Does anyone have a solution to this that requires minimal work? Thanks!