I only see one edition and that one does not have an ISBN. I see another edition which you have deleted, perhaps that was the one with ISBN? I'm not sure how to undo that and check.
Sorry about that. I have originally set it to Deleted before realizing that I would not be able to reuse the ISBN. I’d swear that I have changed it to the Public status before posting here but librarian change log disagrees so apparently I got it wrong. Anyhow I have changed the edition with ISBN to Public so the merge should be possible now. Thanks for looking into it!
https://www.goodreads.com/work/editio...