I am not at all familiar with the software you are using, but there are a few conventions that must be known and observed for successful backplotting in general.
Most often, backplot software reads only G00, G01, G02, G03 and G90 (absolute coordinate mode) or G91 (incremental coordinate mode). Usually, a G90 or G91 should be posted very early in the code before any machine movements are made. This is essential information for the backplot to be correct.
Secondly, arc movement commands (with G02 or G03 words) can legally use either incremental arc center coordinates or absolute arc center coordinates, depending on the controller, and what mode it is running in (G90 or G91). There is a vast difference in the output of the backplot if the backplot software arc interpreter does not match the original arc center coordinates of the post that created the gcode file.
So if the backplotter has the option for various arc formats, you can try them all until you get the one that seems to give sensible results.