Deliberately difficult gamut colors in macro shot of hex nut

Found it by accident. I was going to move CB1 above Filmic, but instead of moving it, I copied it so I could turn off CB1 and move the new one. When I turned off CB1 SHAZAM!!! Fixed.

Yes, some kind of bug because as far as I could see when I started investigating, you had it set up correctly to do what you wanted.