My paperback and ebook aren't linked on the same Amazon page — how do I fix it?

If you published both through KDP under the same title and author, they usually link automatically within a few days — so first, give it 72 hours before assuming it's broken, because it's often just a delay. If they're still separate after that, it's almost always a small metadata mismatch: the title, subtitle, series info or author name differs between the two (even a stray extra space, or "J. Smith" versus "J Smith"). Go into each book's details and make those fields character-for-character identical, then save. If they still won't merge after that, contact KDP support directly with both ASINs and ask them to link the editions — they can force it manually and are quick about it. One thing not to do: don't create a fresh listing to "fix" it, or you'll split your reviews across two pages.