When viewing certain models in the workshop or on the Mecabricks Library viewer, parts underneath cockpit windows (or any large transparent dome) will appear and disappear based on the camera's placement (opening Captain Marvel and the Asis, as an example, will cause minifig inside cockpit to randomly appear and disappear when moving camera around).
Yes, this is a known limitation of real time 3D engines. Transparent elements are very complicated to handle and use a special pipeline to be rendered. Sorting faces within a mesh to know what to render first would currently take too much time.
Hope one day it can be improved.