I have been through these steps and the error is repeatable. The 'receiving' machine when being synced recognises an attachment has been added to the note but does not actually download it. I displays a 'download' icon on the note in its place.
I had manualy checked all the options on the two machines and they are the same.
Each time I sync it seems to fall shart in downloading all the attachments, e.g.
Created local items: 1.
Created remote items: 2.
Fetched items: 4/4.
Completed: 22/02/2023 21:08 (19s)
Fetching resources: 3/24