ApplyMetadataTemplate behaving oddly - dropping existing metadata fields and not adding fields defined in template

This is my first post to this forum, and first I wish to thank those who provided code snippets to help folks. That also helped me tremendously in getting started with Bridge scripting when documentation was deficient. I have been struggling for days trying to figure out why my script did not update metadata correctly, then narrowed down to some odd behaviors (perhaps it only behaves as I instructed it to do).

0. In Bridge, create a template to add common metadata info such as author info, copyright

1. In Bridge script: Update metadata of an image - event location, headlines etc.; then

2. ApplyMetadataTemplate (append) to the same image to add common fields such as author info and copyright;

Result: Fields added in step 1 were wiped out; some fields identified in the template were added (creator, copyright status and usage terms), but some did not make it (creator state/country/email/website). I had expected that metadata added before applyMetadataTemplate/append would be retained, and all fields specified in the applied template would show up.

I would appreciate any help to show me where I went wrong. Below is a code snippet that illustrates the problem, followed by a diff of metadata dumps before/after ApplyMetadataTemplate command. The test environment: Windows 10, CS6.

var image = "C:/_testBridge/test1.jpg";

var thb = new Thumbnail(image);

var md = thb.synchronousMetadata;

if (!ExternalObject.AdobeXMPScript) ExternalObject.AdobeXMPScript = new ExternalObject('lib:AdobeXMPScript');

var xmpf = new XMPFile(File(image).fsName, XMPConst.UNKNOWN, XMPConst.OPEN_FOR_UPDATE);

var xmp = xmpf.getXMP();

xmp.setProperty(XMPConst.NS_PHOTOSHOP, "City", 'myCity');

xmp.setProperty(XMPConst.NS_PHOTOSHOP, "State", 'myState');

xmp.setProperty(XMPConst.NS_PHOTOSHOP, "Country", 'myCountry');

xmp.deleteProperty(XMPConst.NS_DC, "description");

xmp.appendArrayItem(XMPConst.NS_DC, "description", 'myDescription', 0, XMPConst.PROP_IS_ARRAY);

xmp.setQualifier(XMPConst.NS_DC, "description[1]", XMPConst.NS_XML, "lang", "x-default");

if (xmpf.canPutXMP(xmp)) {

        xmpf.putXMP(xmp);

        var xmpObjectInfo = Array;

        xmpObjectInfo = xmp.dumpObject();

        $.writeln('Applied event metadata to:     ', image);

        $.writeln(xmpObjectInfo);

}

xmpf.closeFile(XMPConst.CLOSE_UPDATE_SAFELY);

//append additional common metadata -author information and copyright

md.applyMetadataTemplate('Test', "append");  

var xmpf2 = new XMPFile(File(image).fsName, XMPConst.UNKNOWN, XMPConst.OPEN_FOR_READ);

var xmp2 = xmpf2.getXMP();

xmpObjectInfo = xmp2.dumpObject();

$.writeln('AfterApplyMetadataTemplate-------------------------------------------------------------------------------------------------------------------------');

$.writeln(xmpObjectInfo);

xmpf2.closeFile(XMPConst.CLOSE_UPDATE_SAFELY);

Diff result: Fields dropped are highlighted in red; fields added by ApplyMetadataTemplate are highlighted in Green. A large section of the data is omitted.