Phil1

Ok this fix will sound weird but fixed the left click issues for me completely. I've replaced the M65 firmware multiple times from a support ticket, reset the mouse, changed between USB2 and 3 ports regularly. Some of these seemed to work for a few minutes and was back where I started. Gaming and doing graphic design was impossible. I did the fix below over a month ago now and it's been perfect. Fix: It's not the electronics, it's that thumb panel (left hand side of the mouse) If you wiggle it you will see there's some play in it. I found that panel was pushing down just enough to lift the sensor off the pad making the left click hit and miss unless you push down with some pressure. I took a piece of sandpaper and sanded the bottom ledge of this panel (under the mouse) It's like a carbon material so sands very well, just don't get the black dust in your sensor cavity. This makes for better clearance and solved all clicking issues I had with the LMB. Hope this helps someone with their problem.