Brakes on 2003 Volkswagen Jetta

When I start my car sometimes I can't get
it to go into reverse the Automatic stick
is stuck and won't move until the car is
warmed up. The little shoe on the dashbroad and the little shoe on the stickshift go off but does not let you shift. Can you tell me whats wrong. I had this problem fixed twice and they are
telling me it is a sensor.. But I feel like I need to find out more about this
problem this is my third time.

Unfortunately, transmission failures in Volkswagen Jettas are not uncommon. RepairPal includes a couple bullets on the problems on its Jetta page:

In most cases, it looks like, significant repair work is needed to resolve the transmission problems.
1 more answer
When you step on the brake pedal do you hear/feel a click in response at the shift lever area ? Can you depress the button on the shift lever , with the brake pedal depressed ?
If not the shift lock mechanism at the console needs help.....