This has been discussed so many times on the forum and, of course, it's NOT a GSX problem or bug. It's a very well known bug specific in P3D 4.2 which happens with every application with a menu, including LM own sample from the SDK, which causes menu options being automatically selected if you (or another addon) has sent a numeric key before.
To prevent this:
- Don't press any numeric keys before opening ANY (not just GSX) application with a menu
- Don't assign numeric keys to 3rd party applications that might use such keys on their own, for example Chaseplane's camera views.
Again, the problem is totally unrelated to GSX, it affects each and every application with a menu (like SODE, FS Passengers, etc.), there's nothing we or the developers of such other affected applications can do about, LM IS aware of it, and it will fix it in the next update.