Oh those screen captures are beautiful! I am not sure I understand… what do you mean by “properly mapped” ?
You treated the images as if they were REC709 which is a small REC709/sRGB color gamut and SDR dynamic range, but the images were stored as full REC2020 which has a wide REC2020 color gamut and HDR dynamic range. If you do that then the colors become very dull since the same coordinates in REC2020 gamut in REC709/sRGB gamut are much to close to unsaturated and not far enough out and also the black and white points are different so it looks dull and low in contrast. You need use something like MadvR and set it to playback converting to REC709.