Lately after moving processed images from one folder to another I've found stray xmp files in the original folder. I've verified the files in the destination folder have xmps. The ones left behind seem to be basic xmp files with just info PSu may assign when importing the RAWs as they don't have any catalog labels, headline, etc.
They don't seem to be left over from all the files that were in the original folder, just some of them.
Any thoughts why they would exist?