A bug in S1 Toolbox, Range-Doppler terrain correction

Hi, I would like to report a bug in “Range-Doppler terrain correction”. It appears in “Range-Doppler terrain correction” operator. When “External DEM” option is selected the dialog window shows the option “Apply Earth Gravitational Model” as not selected, but actually it is set as selected in the algorithm.
The bug is in RangeDopplerGeocodingOpUI function, lines 405-409.