3.3.7435
I was in the tag editor, tagging a boxed set that has oddly named individual cover art for each disk that is stored in the subfolder for the disk.
Selected files, opened tag editor
right-click art->Choose Picture
chose picture
Selected "Link picture to this music track" (multiple tracks were actually selected)
Selected "or link to the original picture file"
Selected "choose the same next time without asking"
OK
Back at Tag Editor, Save
This worked fine. It linked the files to the original picture.
Then I moved onto the next disk
Selected files, opened tag editor
right-click art->Choose Picture
chose picture
Back at Tag Editor, Save
Should have linked to the original file selected for this group without asking, but a Cover.jpg was created instead.