I get this problem of one or both door pillar cameras being 'blocked or blinded' from time to time, particularly when the sun is bright and low in the sky. It is made worse if there is any condensation droplets inside or outside the glass on the door pillar in front of the camera. It usually is transient however and clears up by itself as you drive, but it is definitely annoying.
I have wondered about things that could be done to mitigate the problem. For example, having a small lip / visor over top area above the camera to act as a sun shade, but without obscuring the view the camera needs to get of the front and side areas!? Maybe some sort of silica pouch could also be used to absorb moisture inside the glass and prevent it condensing on the glass and refracting light, which I think is a frequent cause of blinding the camera transiently, especially on damp, foggy days. Anyone got better suggestions?