What size tires were OEM and what size did you replace them with? What's the recommended psi per the manufacture stamp in car door? What is the max cold psi as labeled on tire? If the max cold psi rating on the tire is higher than the recommended psi by VW then run the tires at the psi labeled in car door.
My 2008 shows tire pressure even when low. If you have no reading then it is a low battery or damaged sensor. The last time I had tires replaced, the psi reading was displayed before I left the Costco parking lot. How old are TPMS sensors?