Makes sense. Sense in a way that it refires. I assume you just do not sulk and sit on the bike trying to fire it. The times you light it off is when there is no seat pressure on the box. Even if it shorts and/or grounds more likely, the black box returns as if no hard part burned out on the motherboard, nor something heating up and lifting off the motherboard to stop current flow.
So it's a safe wire chafing as if using a kill switch and no harm to the component, to the pin moving in the connector and returns seat wise, road bump wise. Zip-tie cutting and flipping the box to see the connector or wires resting on whatever.
1. When flipping the box over, do not wipe wires with a rag just yet.
2. The visual is a powder of wire covering or paint etching at the frame to ground.
3. Rub both hands together; which hand stayed cold? So it is equal wear at 2 touch points you can chase down... finding the one side being the obvious.
4. Now with a rolled up paper towel looking like a pencil, drag down at the wires, meaning, X is where the pillows would normally lay on a bed. Where Y is dragging the paper across the whole bed and missing the powder being removed by the rubbing.. if... you cannot obviously see it.