A white box occludes the ACO sight when switching from 3rd person to optics mode. It appears to be related to loading the texture for the reticle. This bug only seems to occur after the game launches, and can be reproduced consistently in the Combined Arms showcase. The box is actually in front of the ACO, though this is not apparent in the attached images.

The attached images represent a sequence of events (1 -> 2 -> 3 -> 4). I was unable to upload an mp4 despite it being only 600KB in size -_- {F20121} {F20122} {F20123} {F20124}