Hello.

I am glad that the issue was solved.One reason would be that there is some minimal scaling factor beyond which the regions are already too bright to be detected/processed with no issues.
This minimal factor might be smaller than 5 in your case, and hence the quantification for different factors that you chose are all close.
Although there is no 'optimal' way to choose the scaling-up factor (5 vs. 10 vs. 15 in your case), I wonder if the best one might be chosen visually on 1-2 images/detections?
Since, this is a post-hoc check, and the variation in quantifications are minimal, the results would be valid for any down stream analysis.

The NaN issue comes from the Matlab typeset for exporting/importing a text file from mat files (or Matlab's workspace). There might be other reasons, but feel free to convert number precisions as needed since this has nothing to do with the detections. Thanks!