Have you actually verified the light is too low using the proper checking method, or are you just going by what you see (or don't see) as you're riding down the road? If you do the official alignment check and the beam is below the target, and you can't get the light to adjust any further, there may be a bent, broken or loose part in the headlight assembly or adjuster.
Btw, the official test method I'm talking about involves a flat level surface and and vertical surface like a wall or garage door. With someone sitting on the bike and holding it level side-to-side, and the front wheel 25 feet from the vertical wall, measure the height of the center of the headlight from the ground, then transfer that measurement to the wall and make a level horizontal line (painters tape works well). Fire up the headlight on high beam, and the hot spot of the light should be centered high/low on that line. When you switch to low beam the top of the hot spot should be just below the line.
Jerry