Unfortunately, they are not writing the codec name properly. I suspect it’s some sort of uncompressed codec, and from your description of the problem, I suspect it’s uncompressed YUV.
Resolve (and FCP) interprets this as video-range data, and that’s why the Auto setting treats it as such. If you want to override the behavior, you just select all the clips in the Media Pool, and force the levels to full-range.
Hopefully this fixes the problem for you!