cookprocesscount doesn't work well

Hi! I would like to know more about cookprocesscount. For example, now when I try to build my project with cookprocesscount=3, I have a lot of time for full cook, and if I want to use incremental cook, I get a time equal to full cook. If I use cookprocesscount=1 I get better time for incremental and full cook WHY? 0_0. I use UE 5.5. Does cookprocesscount work well in this version?