Does your code work as you’ve written it? I can’t see how that would come about, as your definition of the cover link, should be:
---
cover: "[[image.jpg]]"
---
The point being that if cover is properly defined, you should be able to do cover.path within your dataviewjs script directly to access the different parts of the link. Try doing a console.log(cover) within your script to see how it behaves.
Still you’re entering a shady part of dataview with embedding stuff, which is a little bit random at times, as I’ve (and the issue I linked) indicates in this answer: