I had this happen. I was using my default throttle config with both mixture and prop rpm controls. I just left them at the maximum setting and didn’t use them.
Turns out the slightest - and I mean SLIGHTEST - movement of either of those will cause the engine to shut down. This also occurred for me in the Citation. I suspect it could also have an effect in other planes that don’t use mixture and prop controls.
What I ended up doing was saving out a separate controller config for my throttle where those 2 unneeded options are disabled. I switch throttle control layouts based on what plane I’m flying.
I haven’t had the problem since.
EDIT
I discovered what the issue was, but won’t take credit for the solution. Someone else had recommended I save out a separate config for my throttle. Sounded like a hassle at the time, but turns out it was dead simple and only takes a few seconds to switch when I switch aircraft.