Here’s a sample of an image taken with a Nikon D850 a few years ago (so it should be using a well-worn NEF format). It’s supposed to be two eagles going at each other.
Every image I’ve tried with DeepPrime comes out looking similar to this. If I use just Prime, all seems fine.
I’ve tried converting to DNG first, same result.
My graphics card is a GeForce RTX 2070, if it matters at all.
Since DeepPRIME relies on the graphics processor when possible, that could be your culprit. Make sure PureRAW is configured to do that and that your nVidia drivers are up-to-date. (I use the Studio driver but the Game driver should be fine also.) If the problem persists, run a test program such as FurMark to rule out a graphics card malfunction.