On several occasions I have encountered an issue in which the red dot of the red dot sight finds itself out of place.
The red dot is in the correct place when I am looking through the optic and it does not affect the functionality of the sight, but when not using the sights it will sometimes appear near the crosshair. It looks to be a cosmetic problem.
This has happened on more than one occasion. I'm not sure how to intentionally reproduce the problem, but if others have experienced this maybe they can shed some light on what might trigger it.