I think maybe you need to re-do this with closer to 25% warm in mid/hLs. You can do this simply in the sliders in QTR if you are making a “neutral” just with the Warm and Cool curves. Or you can use the stock cool curve and simply tune it warm or cool in Highlight/Mid/Shadow with the sliders in QTR. This can be your reference setting for building a “hard-coded” neutral curve with the PPEv2 tool later on.
Also, always measure in D50 mode too. ColorPort exports data by default in Illuminant A (not d50).
Also, the very base shadows always go a tiny bit warm due to 100% carbon at the end (most archival and darkest black).
Neutral is always the a hardest to achieve . . . . .