Are you able to look at the browser javascript console while replicating to see if there's any javascript error being logged?
If there's no javascript error, then I doubt my extension causes the issue. It's normal for the same fish/bunny images to be visible on the duplicate profile since it's the same user ID and therefore the same profile card with the same fish.
If there are no errors, I would suspect it has something to do with the sort order not being entirely deterministic. The problem seems to happen when sorted by discussion count, and the issue happens on a pagination breakpoint, all with users that have 8 discussions. It's possible Flarum doesn't always return those 8-discussion users in the same order, and so the page break caused another user with 8 discussions to be skipped and one came as a duplicate again due to the random sort within the discussion sort.
Your user list doesn't seem accessible to guests so I cannot replicate on your forum, but I might be able to test this on my development forum later.
