First question and I am assuming it is answered in your post as a "Yes", is were the shots fairly consistent?
Glock does have several factory sights that raise and lower the impact. And by sliding the rear sight one way or another, either left or right on the back of the slide, will move the impact right or left.
When you install aftermarket sights you settle on one elevation, which by the way is the factory installed out of the box elevation of the Glock plastic sights, middle ground.
More than likely you are suffering, and I don't actually mean suffer, from the "New sight" disease. Meaning, like a golfer with a new putter, it either gonna make you game of screw it up.
It is all mental. Get a couple of sandbags, have a good firm solid bench rest hold on the gun. Squeeze the trigger straight back, with the ball of your finger, not the joint crease, and try to make holes right on top of each other. ONCE you get your trigger control down, THEN have the armor move the rear sight in the correct direction to compensate for the windage.
MOST people who shot glocks for the first time (right handed shooters) will pull the shot down and to the left, until they learn the trigger.
Get the sand bags, shoot a group of 10 rounds as tight as you can get them. THEN see about rear sight movement.
The more you shoot with it the more it will shoot where you point it. that just takes practice and time and rounds OF THES SAME AMMO and similar conditions.