Nikon Z9 Issue—Aperture Setting Gets Smaller While Shooting

I use my Z9, D500and D850 the same way. I set Aperture Priority, Auto ISO and set the minimum shutter speed in Auto ISO.
 
My problem is that with the Z9, with the Nikon Z  mount 100-400mm S lens attached,  I found that the aperture I selected sometimes changed.  If I set f5.6, it sometimes goes to f16 and smaller. I thought maybe my finger was inadvertently changing the aperture by turning the front command dial. But that does not happen with my D500 and D850.

I did not think I have set anything on the lens or the camera that could be causing this. But after checking lens settings in Custom Settings f2, I discovered that Lens Control Ring was set to Aperture. I changed that setting to Off.  And that seems to have resolved the issue. 

If you own and use Z mount tele lenses you might want to check all of the lens settings and make sure they are what you want.

Thanks for the info Joe. (Only came across that once, but have chosen to leave the setting to on, as it's quite handy. Just a reminder to watch what I'm doing with the hands..LOL).. The 400 4.5 and 800 6.3 have the lens ring moved further up the barrel whereas the 24-70 F4 is closer.