Do you have a local independent VW mechanic? Dealers are generally OK, but they are more expensive and not better than independents.
I don’t recall what year they changed, but later model VWs have a special computer access that requires a special tool (VAGCOM) to talk to it to find out what is going on inside. Most general shops will not have it. Also experience counts so having someone who specializes in VWs helps.
Any corrosion on a connector can cause such problems. You may want to try just cleaning it off. Note: cleaning the outside is not enough, you need to get the contact surfaces clean. VWs are known for this kind of problem.