For OS security reasons, the file was not able to be moved but was only copied to the specified destination. Use another file management application to delete the original file.
For Android 11 or later, along with the security enhancements that are made for the operating system, it is possible that access rights to the file have been lost.
The file was copied to the specified destination, but it was not deleted so it remains in the original folder.
If you want to delete the file from the original folder, use a file management application.