Ihave a 1998 528i BMW 5 speed and All gear work beside reverse please help on 1995 Volkswagen Jetta

I can go into 1st 2,3,4,5 but won't go into reverse

Asked by for the 1995 Volkswagen Jetta
get diagnostic run. could be sensors. could be mechanical. get it scanned.
Thanks I plan to do that, but still want to know why it just stop going in reverse but still goes into 1st 2,3,4,and 5th but I just don't know was searching for help