It's likely the Fenix having detected the raise of the front gear or the very fact the airplane is moving as a "landing", so it enabled whatever automatic system it has for that event.
If the event is caused only by the pushback raise, you can fix this in GSX by disabling it in the Airplane configuration page. But if the problem is the movement itself, there's nothing we can do on our side, but Fenix could read the GSX variables that are set when GSX is pushing, so they could possibly disable all these systems during the pushback.
