If that’s the front then what order did you attach it to the car? Bottom clips first the. Pre-drill a small pilot hole? If so, pushing too hard on the drill will force the liner to flex away from the wheel which causes the pilot to be closer to the outer edge which would result in the splash guard getting pushed out. Remove the screw and push the guard against the body flush and see how much further in the screw needs to be, drill a new pilot and go with that. Hopefully you have enough room to do that. If it’s too close to the existing pilot, you may need to fill it with some kind of epoxy or glue gun type of material first.