I originally bought GSX 2 years ago and this problem made me ditch it. Now I've come back to try it again and its still there, in this case with the q400 at EGNX. The top pic shows how it starts off, the bottom pic shows a second later when the viewpoint is slightly lowered - no other changes.
Well, you shouldn't expected this would automatically fix itself after one year, because it's not obviously a GSX problem. It's an automatic optimization that FSX does, to remove objects that it judges to be occluded by something else.
If you change it to go closer, by leaning forward the screen with the Track IR, FSX will *think* the objects should not be visible anymore, and doesn't draw it anymore.
The problem doesn't happen just with GSX, of course, it happens even with default jetways, and any object that goes very close to your viewpoint, it's just there aren't so many objects that gets the chance to get so close to your airplane as the GSX one (especially the pushback), so you can be easily mislead this has anything to do with GSX, but it's not, and we don't have any control over it.
You can TRY this, open the following file with Notepad:
%APPDATA%\Microsoft\FSX\Cameras.CFG
- go the camera definition (es. [CameraDefinition.002] ) with title="Virtual Cockpit"
- add the following line to its section, just before the next camera definition:
ClipMode=Minimum
- Save the file and see if it makes any difference. If it doesn't, try with ClipMode=Normal, which is the default setting.