This info is located in the history of the normalized file, right-click > File > View file history.
It will show the normalization method and the time window, it will be one sample if the window duration is zero of 1/fs
Solved! The problem is your noise covariance.
The noise covariance matrix for the CTRL01_L_1K60_2_Z_band was manipulated outside of Brainstorm. Not sure why this was done. What was tried here? There may be a way to do it using Brainstorm.
Compare the contents between the noise covariance in the folder that is working and the problematic folder. As you will see, the problem noise covariance content is missing fields, among these nSamples which is required. This was hinted by the warning
Warning: Variable 'nSamples' not found.
that appears in the Matlab command window when computing the sources