Hi,
It looks like it’s only happening to that one single post. I’m not sure why or how, it looks like if it was some sort of duplicate, but with the same URL. Have you imported posts by any chance?
Can you please add temporary FTP access as well? I would like to debug the search query to see what post ID that strange result has. I believe it might be some sort of post revision or something that has been stored incorrectly, but I’m not sure.