Navara stx no Reverse gear

[Reidy]

Gday gents,
I know its not a Patrol but considering the great advice I got on my patrol issues I was hoping someone might be able to tell me what might be causing the Nav to not have Reverse gear?

Every other gear works perfectly just cant find reverse. I have been through a few threads and from what I can understand it may be the selector plate. Would I still have forward gears if this was the issue?