Check continuity on the kill switch and button(s). I’ve seen both randomly fail once wires are stressed and even the little metal rocker in the switch come loose once pressure was on the kill-switch shell. Fill in the rest of your solder points, you don’t want divots where the solder isn’t secure through both openings. Finally take a closer look at that solder near the mosfet to be sure nothing is touching and shorting out at the mosfet leads. Check both sets of mosfets, here’s a reference.