Many times that twisting comes from striking at too much of an angle and swinging too hard. With the kukri shape you do not need as much of an angle to get the job done and you should not swing for the fence. Use only about 40-50% of your strength with each chop and use only a slight angle. Also, be sure to check out the material that Karda provided above and find the kukris sweet spot. That is where you should be striking and it is where the blade is at its most efficient, hardest and produces the least amount of vibration.
Also understand that what you have is a kukri machete, not a kukri. A machete is designed to cut foliage where a kukri is meant to cut bigger harder material such as wood. You "can" cut wood with a machete and you "can" cut vines with a kukri but it gets unsafe and less efficient. You also run the risk of injury when you use each in jobs they are not designed for. Many many people break machetes batoning wood and using them to do jobs they were not intended to do. This is why one costs $25 and the other costs $200.