I have the same problem. Right window does not go down. If I hold it from both sides and move it back and forth while having someone depress the down switch, it goes down. It will then work for a while until it gets stuck in the up position again. Motor seems to engage but unable to overcome the force needed to move the glass.
Either a worn regulator mechanism, or it needs adjustment/lubrication, or a weak motor. Are you handy with tools? Not too difficult to fix, look up some Youtube videos and decide if you can handle it. I had to put a motor in my ES300 drivers side several years ago.