Problem with Luke2

Hello. I need your help. I have a luke 2 with the original EMGs. In the intermediate position, neck and middle, the sound is no longer sparkling. It is rather on the dull side. I wondered what the pickup height has to do with this. The heights of all three pickups are 2.9mm on both the bass and treble side. New strings don’t help either. But maybe this duller sound belongs to the guitar? Or is something else going on?