Export spectra to txt file: csv contains NaN values

When I try to export the spectra for the pins I have created in the spectrum view, the .cvs file seems to contain a lot of NaN values. The spectra visually all look fine though, no ‘NoData’ points are present. What is the reason for these NaNs?

With what type of data are you working? Is it Sentinel-2 MSI data?
Maybe it is a related to the multi-size issue we are still facing. Have you tried to open the data at a certain resolution and do the export?