InitialDirectory does not appear to be implemented

[SeanE63]

I am initializing the BrowserProperties as shown:

    var bp = new BrowserProperties
    {
        initialDir = sMap.ModulePath,
        title = "Load Module",
        filter = "Module files (*txt)| *txt",
        filterIndex = 0
    };
    
    then calling the  FileBrowser().OpenFileBrowser.  It doesn't matter what directory I hand for initialDir, the browser opens up in the last directory it was open in.