I too have experienced this same exact issue and requested a replacement unit from Amazon which I received today. Upon examining the newly arrived unit I find it too does not "Left Click" when pushing the scroll wheel to the left. I can't understand the reasoning behind this design decision. Clearly there is a clicking action occurring when the wheel is pressed towards the right so why not to the left as well as many other mouse manufacturers have done. For such a premium product I fail to understand the lack of full use of the wheels potential use cases. I'm going to research this further and will update with my findings.
