I've owned my DSG GTi for about 3 months now, and I've noticed the clutch does indeed feels like it disengages when you're crawling slowly in traffic (10-20kph)
My question is, do you drive in manual mode or in automatic (D) in heavy-traffic conditions?
When you're in manual mode, I've noticed the car jumps down to 1st gear in crawling traffic,
and when you're not gentle with the throttle, the car jolts as the clutch engages again.
But when you're in automatic mode, the car stays in D2 (second gear) most of the time, and while the clutch feels like it is still disengaged, the pick up when you press the throttle is much more gentle.
I hope this helps

I usually drive in manual mode, but when I'm in stop-start, crawling traffic, I leave it in D as it is much smoother.
The DSG sometimes gets confused in roundabouts or heavy traffic as it refuses to engage the clutch back again, and you just need
to be gentle and give it some time for it to make up its mind!