Using the standard "Location" metadata tab, I entered location information. In this case, I just entered the Country. I did a write-back and it reloaded. The Country name then became blank ({File.MD.Composite\Country\Country\0}).
Even though it was blank, "United States" was in the following fields:
{File.MD.IPTC::ApplicationRecord\101\Country-PrimaryLocationName\0}
{File.MD.XMP::photoshop\Country\Country\0}
plus this had the value within XML:
{File.MD.XMP::iptcExt\LocationShown\LocationShown\0}
So why doesn't it show up in {File.MD.Composite\Country\Country\0}? Is there something I have configured wrong? This behavior is true for the other location fields, as well.
Here is a link to the JPG:
https://www.dropbox.com/s/n1mtnw5bioprhbm/P0009199.JPG?dl=0
Here is the EXIFTool output:
-overwrite_original_in_place
-charset
FILENAME=UTF8
-m
-P
-use
MWG
-charset
ExifTool={PTETCHARSET}
-ex
-sep
-XMP-photoshop:Country=United States
-XMP-iptcExt:LocationShownCountryName=United States
-IPTC:Country-PrimaryLocationName=United States
-XMP:CreatorTool=photools.com IMatch 5.6.0.12 (Windows)
-xmp:InstanceID=xmp.iid:109883aa-ced3-4ee4-8930-87c8bf98b54e
-XMP:MetadataDate=now
-XMP:ModifyDate=now
M:\Users\Anthony\Pictures\Library\PIX\P0009\P0009100\P0009199.JPG
-execute
-execute9999
1 image files updated
I downloaded your file and added it to a database.
The Metadata Panel shows "United States" for country in the 'Default' layout ({File.MD.Composite\Country\Country\0}).
Looks good.
I added data to all other geo tags and wrote-back.
The data is saved in the file and also properly re-imported.
Looks perfect to me.
It seems to do the right thing with MWC compliance turned on. I have that off because it takes a long time to write-back.
Don't turn it off.
When you then use the Comp tag, ExifTool will propagate that value to several other values, but on re-import the value may be overriden. I don't even test this.
Disabling MWG is a really had idea because it will often create un-synchronized and broken metadata. This option has been added for very special purposes and for users who know about metadata.
If you have mentioned that you have MWG off, we all could have saved some time...
Updating a file with MWG enabled takes maybe a second. If you work with large 100 MB+ files, maybe two or three seconds. But it's done in the background and you don't have to wait for it anyway.
Mystery solved!