Error when opening csv file

Hi, I am new to SNAP and I am trying to use Sentinel-2 to read the surface reflectance of different types of objects in the ocean.

I am able to create a spectrum view of the wavelength v db but when i save it as a csv file i get an output of NaN for over half the bands.

does anyone know why this is even though I can see the 13 bands plotted correctly in SNAP.

Thanks

Jira ticket SNAP-3586 created.