Weird bolt heating up randomly

The bottom left bolt of the stack randomly heats up? Never happend to me before any clues as to why?. FYI the frame is a hyperlow cg frame with one of its mounting plate replaced by a matek bec/pdb facing down. The mounting hole tested negative from a continuity for a short but its grounded.

You could have a short across the carbon.

Check all your connections. Something isn’t right

I found the culprit however my flight controller got fried and found faulty. Thanks for you reply.

glad you found your fault…

What was it in the end?

It was the steel nut on top of the BEC(touching the vcc esc pad). Sorry I took too long to respond.