In T218511#6065425, @kostajh wrote:

There is a remaining issue, that might be deserving of its own task:

• you are watching an article
• someone makes three edits to that article with revisions 2, 3 and 4
• revisions 2, 3 and 4 show up on your watchlist because you have the "Expand watchlist to show all changes, not just the most recent" preference enabled
• revisions 2, 3 and 4 are in bold / unseen, as expected
• you click on the diff for revision 2
• you reload the watchlist, before the updateWatchlistNotification job has executed
• expected behavior: when reloading watchlist, revision 2 is marked as "seen" and revisions 3 and 4 remain "unseen"
• actual behavior: revisions 2, 3 and 4 are marked as "seen"
  • addendum to actual behavior: when the updateWatchlistNotification job (which was created when you clicked on the diff for revision 2) runs, the watchlist is now in the correct, expected state where revision 2 is marked as "seen" and revisions 3 and 4 are marked as "unseen"