So this is a jpg file which has been shot as jpg AND B&W in camera?
If so the B&W 'style' is presumably burned in to the jpg file. (If is was a RAW file the Camera Film Style would be applied as an adjustment to the RAW values but could be removed or replaced. The same goes for the White Balance settings.
For a jpg the Base Characteristic files settings can only be 'Linear' since the values are burned in to the file. The "Auto" selection will, in fact be the only selection available - "Linear".
It's interesting that you see the see the same problem in other editors.
Also that the appearance on my system opening the file in a session with and without import and it made no difference - the image appeared as a regular monochrome image with no sepia tint.
HTH.
Grant