Welcome to Android Central! Which memo app were you using on the J1? Did the A5 come with the same one? How did you transfer data -- using Smart Switch?
If you're talking about the stock Samsung memo app that came with the phone (i.e., S Memo or S Note), it's possible that the newer phone doesn't have the same memo app, and therefore your old notes may not be compatible. This is why I always recommend against relying on the stock note-taking apps. They often use a proprietary format that is not compatible with any other app (even from the same manufacturer), and sometimes can't even be backed up easily. Stick with an app that is compatible across platforms, like Google Keep or Evernote.