Tai Chi, Hatha Yoga, QiGung/Chi Gung all are practices, arts none of which recommend any practice before bed. At best they get the heart rate up, the respetory system going faster. As such they'll raise the body temperature which is the opposite of what you want to do if you wish to get any sleep.
Early evening, early morning, organs get twisted, the body turns those organs on, gets muscles working and activates them to function just a little more than their usual state. Blood flow increases. There is a good reason early morning are recommended, as is early evening... practice is cooler, more comfortable than in the high heat of the midday sun/humidity.
Neither is even close to a cure, or there would be a huge line to every guru, every shifu on the plane who taught any of them. Keep hoping to find one though... if she/he can cure it for me, I will become family and never leave their side -lol-