I'm fairly certain this is a malfunction. The rear dial is super sensitive and delicate. The rest of the camera isn't too solid either but that dinky wheel in particular is very prone to issues like this.
I had two S9s, one of them did not have this problem but the second one definitely had it. The previous owner put that in the disclaimer and as per him the solution was to rotate the wheel rather slowly in clockwise direction. I can confirm it works but still not 100%. Anticlockwise rotation was fine, just like yours. If you look up Reddit or other forums you'll see a sizeable chunk of people reporting this same problem within few months of ownership. This should be a recall by Panasonic at this point. No wonder these bodies are tanking in price. Such a shame because I loved the size of that camera.
