Preview artifacts with .DNG (RAW) files

Hello there, as in the subject I'm in stuck trying to obtain a true image preview when open a raw file in...preview....

I'm on a 16" MBP 2019.

This is what I get when opening the .DNG version in Preview:

First of all: why is there a line in the middle of the picture and it disappear if I resize the preview?

Second (but that's the principal question): there are several automatic adjustments that Preview does, such as saturation, graduation, white balance, eccc). I want to disable this function.

That's the same .DNG, opened in an editor, that I know the camera shoot:

So, how can I avoid that?

Plus, questions: is there a way to open direct .GPR files with preview? Any other free third party softwares to accomplish that?

Thanks and have a nice day!