Just got my Instinct 2x and I have noticed that the gesture mode is very unresponsive, is this an issue with software or is anyone else noticing it. Only works half the time.

Do you wear the watch on the wrist that is set in the settings ?

I find it’s hit and miss when I’m laying down and I view the watch. But I don’t think it’s the watch’s fault for that, I think it’s just a position that you’re in when you’re viewing the watch. Standing up, I haven’t had an issue at all.

Yes, it seems most problematic when sitting down, standing up it seems as if the gyroscope (which I assume triggers it) senses enough movement that if works reliably.

Yes.

I agree with this, I feel as I am often doing a wrist-snap 3 times to get the gesture backlight to trigger on my Instinct 2X Solar Tactical.
My Fenix 6X Pro was buttery smooth and intuitive to my subtle wrist movements. I even recall my old Instinct 1 being less difficult to get gesture backlight to work. 

So I just fitted a tactical nylon band and I think the gesture is a bit better with it on, I find that you need to flick that is roll the wrist forward and then back, seems to work most times.