The fender cameras are susceptible to water build-up which blurs their view. My MX looses NoA capability on > 1 hr freeway drives in moderate to heavy rain. I get messages that the left or right forward cameras are obscured or not functional, and when I stop to check they look fine with nothing blocking them. I've reviewed recorded fender camera data and observed the blurred view.
I'm not sure what to do about this, but Tesla should be working on some sort of fix if they expect FSD to work in rainy conditions.