Hold switch in up position
I had that problem. Pull the window switch up past the resistence point and hold it there. The window will roll up, then back down and then up again. It goes up almost all the way and if you continue to hold the switch up it will ease up the last little bit until it's fully closed.
It's the "pinch protection" that's causing it to roll back down half way. It thinks it caught your finger or something. Holding the switch up overrides the pinch protection system. It's in your owner's manual if my description doesn't make sense.
When it happened to me I planned on taking it to the dealer, but it never did it again. Just had a problem that one day.