This is probably resulting from the eddy-current correction already performed on the scanner (if the exam card option is set to ‘Apply Spectral Correction = YES’). Essentially, Osprey doesn’t know because this setting isn’t saved in the exported files, and therefore assumes it has to apply the eddy-current correction again.
Try adding the line
opts.ECC.raw = 0;
to your job file (or if you have it already in there, change the value to 1) - see also the template job files in the exampledata folder.