Motherboard won't boot if USB3 on rear IO is populated

This motherboard keeps crashing and giving me the USB bug code message. And if any USB3.0 on the rear IO is populated, it won’t boot at all. Sometimes after a crash, I have to disconnect anything in USB3.0 on the front IO to get it to boot, then I can restart and connect it again.

I am not 100% sure it’s the motherboard’s fault though. The CPU (4930K) and my RAM was on another board before where the AIO leaked slowly over time (the motherboard was horizontal) and I can see the traces of the liquid on the board on both sides, which is why I eventually swapped boards.

Does anyone have any idea how I can maybe figure out what’s up here? It doesn’t matter if it’s an fresh Windows install, it’s the same regardless.

Oh, btw, the motherboard is the ASUS P9X79 PRO.

I have a ASUS P9X79-E WS which dropped to the floor, and a pin or two is bent in the socket, so I haven’t dared try it again. Could it possibly kill the CPU, or just not boot if actually broken? I have tried to fix the pins somewhat.