Is it a bug or a feature

I recently ran into a problem with https://digikam.org sidecar files and ZP.

I activated the https://www.zenphoto.org/news/xmpmetadata/ plugin. (Thanks for that!)

When adding a picture and the sidecar in ZP, then ZP does not recognise the file.
Then I opened the picture (did not modify it) with Darktable and closed the image.
The existing sidecar file was automatically modified by Darktable.
Now I replaced the sidecar file in ZP with this modified file and then ZP was reading this file.

By comparing both xmp files I saw that Darktable has put this

in the first line of its xmp file.

Now I took another digikam xmp-file and was just adding this line

in the beginning of the document.
Now ZP was reading the content of the digikam.xmp file.

Any idea which command in the plugin must be modified, so it does not require upper line anymore?

Thanks.

And yes, I know I should speed up things and upgrade to ZP 1.5.1

Since we talked already, I tried both test files you sent and both worked here.

The file is actually plainly read as a text file via the PHP standard function file_get_contents(). So perhaps it is something server specific requiring the XML definition. The plugin itself does not.