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?