Comma, Period, X, Y and F11 are reserved for TruckersMP. The trailer/axle lift might be assigned to one of the mentioned keys. Make sure that none of these are assigned, as TruckersMP will take priority over these keys and any function assigned for them won't work. Comma and Period change the CB channel, X activates voice chat(in proximity and on current channel when held), Y toggles the chat window, F11 toggles visibility of everything from TruckersMP's GUI.