Some NLP convert previews in v2.4.2 are grayscale?

A few months ago I was dslr (canon 5ds-r w-ef 100mm f2.8 macro) scanning some black and white negatives (Raleno light panel), but wanted some tone to them. I’m not sure what I did, but they came out great - though rgb - which is what I wanted. Now, I can not figure out how to just scan a normal color negative to get a normal excellent NLP color conversion. I press convert - and the previews are all grayscale. How can I reset NLP back to default settings. I’ve clicked the little blue text "reset, but no joy?


I still don’t know what I did other than moving to another negative - and voila - it’s back. Nevermind


I went back to the problem color negative, and reset its adjustments - and it did the grayscale preview again? This after scanning a couple other frames without issue? Here are screenshot links of
What is happening.

I tracked down the original negatives - a single strip of four frames. I don’t remember ever having shot c41 process b& w film, but that is what happened here. It’s my kitchen - so maybe a friend shot some frames, and then gave them to me? So it is not NLP - just user error.