I had a similar experience and tried a few things to fix this annoyance.
Having never really had this before - I went for the obvious fix and used glass cleaner to clean off any contaminants. It seemed to work for the first few wipes and then back to juddering again.
Annoyingly when spraying the screen wash the juddering would stop - the screen wash must have acted as a lubricant but only for a short time.
I checked the alignment of the blades & all seemed well.
Last resort - I booked the car into VW.
The technician reported that there was a 'build fault' and the wiper blades were faulty. They were replaced free of charge & are now working perfectly.
He did mention that there have been quite a few cars brought in with the same problem. Supposedly the rubber on the wiper blades has gone hard causing the juddering.
I hope this helps anyone with a similar issue.