Contact the Exposure guys, email probably best given the time of year. It’s rare, but it’s not unknown for one to fail in the way you describe. Crucially, Tom and the guys at Exposure will sort you out as soon as physically possible. Fortunately for you, their backup and warranty is 2nd to none, so you’ll be fine.
Just been playing with my new Joystick Mk10 too, Xmas present to myself. Shocked at how much more light it chucks out (not so much the throw, more the spread) when compared to my old Mk7 version next to it. On full 800 lumen mode it’s probably enough light to use on its own offroad, with only the 1.5hr run time against it.