You might try another way to line up your sights:
DON'T try to line up 3 dots and a point of aim on the target, two at the rear sight with one at the front sight, forget the dots. Don't see the dots.
. A human eye cannot focus at multiple distances at the same time.
First look at the target point of aim. Bring the "top" of the front sight up to that Point of Aim. Then just notice the light bars on each side of the front sight are equal sizes. That is on target right and left. The top of the front sight on the POA. Next, Look to see that the "top" of the rear sight is level with the "top" of the front sight. Now just look at the top of the front sight still on the POA.
If you look at the exact target spot first and then do as said above and focus on the front sight your dominant eye will keep you on target.
Now pull the trigger steadily back until the hammer drops moving that front sight as little as possible.
DON'T look for the bullet hole! Immediately Repeat the process and drop the hammer. DON'T see the bullet hole. Repeat one more time.
Now check your group size. 1. It may be low but that doesn't matter. 2. The group should be centered on or above the P.O.A.
That's from having the light bars equal on both sides of the front sight. Having the top of the rear sight even with the top of the front sight insures the verticle spread is the same.
All this can be done by "just focussing on the front sight" after it gets to the "small" target POA. If this done as soon as the front sight is on a very small POA, your group size will shrink with a good trigger pull.
Three dot sights aren't really designed for precise shooting. They are designed for FAST center mass shooting.
The dots are not at the top of the sights, and trying out the method above will group low depending on how the factory aligned the dots. Trying to focus at three different distances isn't possible. Changing your focus from one to the other to the target takes more time and is less precise.
This is just something to try out your pistol and your trigger pull.
Hope this makes sense and helps .