If both of them are freezing up or having issues moving in general, I'd get the wiper assembly replaced. You can pick up and test a scrapyard piece. The replacement itself is very easy on the mk5. I've had an issue on my mk4 where it barely moved. It could only move if unscrewed one wiper completely. The mechanism itself gets rusted or the motor burns out. Had the same thing happen on a A4B7. Replacing it on that was a pain in the ass tho cause everything is so tight.
