I wonder if it is an internal connection inside the box, affected by launch g-forces. You have had problems with the box that you still havent solved.
I would beg,borrow, or steal another box, (hopefully a known good one from a buddy) and try that.
It sounds to me like an ignition problem, not fuel or suspension. My half-fast opinion only.
Yellow rose was generous enough to send me one to test. I also feel like that’s the problem as I’ve yet to find something else while going through everything else in the car.
