Okay, I get it to look good. It is a problem with the configured culture, it seems that it did not use that of the application and used that of the operating system.
It is solved by forcing the culture in the application, such that:
static int Main(string] args)
{
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture("en-US");
CultureInfo.DefaultThreadCurrentCulture = Thread.CurrentThread.CurrentCulture;
CultureInfo.DefaultThreadCurrentUICulture = Thread.CurrentThread.CurrentCulture;
...
It is necessary to do it in each Main function in the source build and regenerate the CSVTools.sln solution.
More info: [CSVToSVG] culture problem - Feedback for Unreal Engine team - Unreal Engine Forums
results:
