When zooming with weapons that do not have a scope in Reach (ie: Assault Rifle, Plasma Repeater), if the crosshair is set to centered, the zoom does not stay centered. The crosshair is centered for a couple frames, but changes back to the default (lowered) position. When zoomed out, the crosshair returns to the proper setting. In the current flight with Halo 4 & Reach, this issue still persists.
Please make sure and file bug reports in the Halo Support site about these issues: https://aka.ms/HaloSupport
If you are encountering issues during the flight, please refer to the known issues list on https://aka.ms/HaloSupportInsider and submit tickets for issues not present.
I submitted a ticket for the issue a few minutes ago. I went into greater detail, and provided some images to better illustrate the problem.