I searched for a similar issue, couldnt find one.
Intermitently, happened twice in the last 3 days.
First time was running slow engine stumbled dash gauges acted like i turned off ignition and then back on, all on its own.
Second time i was try to navigate into a parking spot and it totally shut down.
Turned key off and it started right back up. Samething, looked like someone turned the key off.
Checked battery and isolator, no loose connections.
Thx
Larry
Are you running silver leaf?
Sounds like ECM losing power. Maybe take a look at those connections as well.
Possible intermittent contact inside ignition switch, or cracked/loose connection in power activation wire from ignition switch to ignition solenoid (relay), or failing ignition solenoid (relay).
Check the auxiliary start at the rear, it can cause weird things to happen. If you haven't replaced those switches I'd start there. Mine was intermittent when I would hit a bump then finally just shorted out and killed the engine. You can just unhook the wires and tape them up to check it out.
That's the worst kind of thing to trouble shoot as it's all guessing and changing parts.
Check the little black hose by your fuel filter. Mine was sucking some air. Replaced it and all good
Ended up being the ignition relay in dash in front of passenger seat. Had to bypass, all good till get to shop!