It looks like this post happened twice on lemmy.world and the second was removed, but then we didn't get that removal for some reason.
These are the two posts on the lemmyworld side:
635 doesn't load for me though so I'm assuming it was deleted by admin/mod.
I suspect this is all on lemmy.world's side, they've been having stability problems and haven't updated to 0.18.3 yet either.
lemmy=# select id, name, ap_id, published from post where id in (2238275,2238125);
id | name | ap_id | published
---------+----------------------+----------------------------------+----------------------------
2238125 | Use an issue tracker | https://lemmy.world/post/2355428 | 2023-07-29 20:59:17.029512
2238275 | Use an issue tracker | https://lemmy.world/post/2355635 | 2023-07-29 21:04:12.02136
(2 rows)