Potential scope and rail issues aside, to make it shoot lower use a shim under the FRONT ring. (It elevates the scope, loweres the barrel). Piece of aluminum can cut with shop scissors works just fine.
If the scope or red dot has a cross memeber that fits into the weaver base, make sure it's alll the way down into the slot. If the back one is high, it will make the bow shoot high and vice versa for front.