Remove cyan in CMYK. But it is still there in the PDF

Hi, short brief

Work in Photoshop

source: Coated FOGRA39 (ISO 12647-2:2004)

Exclude Cyan with Channel Mixer

embed profile, place it in Illustrator

Illustrator set for:

CMYK - mode

Source: Coated FOGRA39 (ISO 12647-2:2004)

Preserve Numbers (ignore linked profiles)

Conversion: relative colorimetric (Adobe CMM)

Output: Convert to destination (preserve numbers) = 0.7% Cyan pops up like sprinkle in the areas where i only wan´t tones of magenta, yellow or black

Output: No Conversion = 0% Cyan, like it should be

Set "Off" for "color management policies" = not working

Drop embedded imaeg profile = not working

Question:

Why isn´t "preserve numbers" honored when I save my PDF?

Since I´ve troubledshoot ALOT around this and I´ve googled as much as I possibly could. I only have a few guesses left;

a. I have wrong, the option "Convert to destination (preserve numbers)" still process images even though Illustrator "Ignore linked profiles"?

b. GPU - performance for CMYK-mode in Illustrator is still a beta?

Thanks for your time. If your interested in the topic I can always give you more info. If you have a clear answer PLEASE write