Weird Targeting / aiming View

hello there
i am trying to make FPS Game and use the Shooter game as example.
the issue i have is as shown in the attached photos.
i think its something to do with the view port options but dont know where to find it.

thanx for your intensest

aim02.png is what i am seeking for but what i have currently is aim03.png
and if there nay way i can guarantee that the optic red arrow is in middle of screen.

if i have 2 type of optics

one on top of the other how i can get from the first optic to the second optic ( different in Z axis)

I honestly can’t figure out what is wrong in these pictures - could you elaborate on what you are expecting to see?