I have a Logitech G920. If the throttle is at idle, the vehicle is in gear and the clutch is depressed sufficiently to disconnect the transmission from the engine, the game initiates the stall mechanic. This happens in any gear and also when in Advanced mode. This is a carry over from Spintires and is precisely the opposite of what should happen when using the clutch. It makes low speed crawling difficult as depressing the clutch a little too much, instead of just stopping the wheels, requires raising the clutch and using the accelerator to prevent the stall, which churns up the terrain.
Stall with clutch depressed