Fog when the metar reports CAVOK

Excuse me, but did you look at the first of the 2 screenshots above? I arrive at around 800-500 ft on the approach and can’t see the runway, yet. This is NOT CAVOK… I am a flight test engineer and have a quite considerable experience in cockpit flights and visibility conditions, pilots would laugh at me if I told them that that is a cavok condition…
Further, now ALL the time I have that condition. I have been testing for 2 days and always the same. I can’t believe that’s normal…