Illustrator Recolor not applying the same change to each swatch

ive got a set of swatches that i need to darken up, but i want to darken them specifically using the K slider and thus only increasing the black ink. im trying to make an array of colors that will find a color match for PMS cool gray 5C when printed. ive got 120 swatches and i want to add 5 points of black to all of them.

i am in CMYK color mode, all of my swatches are CMYK color mixes, no LAB or HSB. for example, one of my swatches is mixed as 6, 6, 6, 31. when i grab all my swatches and recolor them by going to the advanced recolor menu, selecting the Edit tab at the top of that window, i put an adjustment of +5K in and that color that was originally mixed as 2, 2, 0, 22 is now 37, 31, 30, 0. 

i cannot find a way to parse this question i feel like im missing some vocabulary, but my goal is just to get the recolor option to apply the exact same change to every single swatch without these massive changes to the color mix