Mine has did this periodically yesterday after jumping some pretty rough waves for an hour. I have pretty much narrowed it down to something electrical getting wet, but haven't figured out what it is.
It only does it after much running and getting water in the hull (I pump it out about every 15-20 minutes and 2-3 gallons may come out if I have been riding hard). If I let the water stay in there and it splashes around jumping waves and making hard turns, something gets wet and the bike dies.
Luckily, i have been able to pull the lanyard, put it back on, and it resets, but not for long, and the longer I keep driving, the shorter the time period before the next stall.
Usually, when these kind of electrical demons pop up, I start heading back toward the trailer because they just get worse until i cannot keep it running at all.
Goes away after I rinse the salt water out of the hull and off all the electrical stuff, then spray down with water displacing lube.
No wave jumping and i can ride all day long with no problems.
So, rinse it all down, be sure all contacts are lubed and tight, and check all those fuses.