A point of interest (and my opinion) is that area has seen moisture and is possibly your issue. The white chalky substance on the aluminum is a tell tale sign.

I had side view camera issues a while back and when I went back to that area, it was soaked. I guess a drain backed up and it allowed water to dump down that rear C frame, behind all the trim, and right on the electronics. Luckily I caught it quickly, stopped it, unplugged everything, removed the modules and let them dry out.

My guess is you have had water damage to a module.