Transmission Stuck In Gear problems of the 2011 Volkswagen Jetta Sportwagen

While driving the car with the dsg transmission in manual shift (tiptronic) mode, the car is supposed to downshift automatically as the car slows down. I have had 2 instances when the car would slow down, the transmission would downshift (as it should) to 4th gear and the instrument cluster multi-function display indicates 4th gear but when I accelerate to get the car moving again, the car feels like it is stuck in neutral, I. E. , the engine revs but the momentum does not increase. Solution: I have found that manually pushing the shifter lever down to shift into 3rd gear engages 3rd gear and gets the car going again.