Here’s how one of the images in question is rendered by macOS/Apple Photos:
Here’s a link to the DNG file proper: https://drive.proton.me/urls/P2WQYS8DKR#H8bXVb4iyvuM
Here’s how it renders in Nitro if I toggle “Standard RAW Development” off:
The sliders I see in the RAW Tuning section in Nitro for this image are Moire, RAW Sharpen, and RAW Contrast, as well as the Gamut Mapping checkbox. Per the EXIF data, the DNG Version is 1.3.0.0 and the DNG Backward Version is 1.1.0.0. I believe (based on the filename and EXIF tags) that I created this DNG from the original RAW file back in July 2012 using Lightroom 4.1 on Windows.
Thanks!