Are you certain you’re keep a target focus? All my red dot guns, the irons and dot don’t perfectly align to each other. They’re separate sighting systems, zero one, then separately zero the other. You’re looking at a front sight through a curved pane of glass, I’d expect there could be the appearance of something looking slightly different. RMR, 507Cs, and 509Ts all do this for me. But I target focus and never notice my irons anyways.