I didn't see this mentioned or maybe I missed it because it almost 3 am for me.
I've noticed that sometimes the post order on the forums gets switched. Specifically in the "X the person above" threads. I noticed it a few times during Morostide as well. The page will load after making my post and sometimes if I reload the page it has a different post above me than the previous. If I reload the page again it might switch back or it won't. Sometimes I get two events for kisses from different people and when reloading the page I see I was kissed by the person below me and the person below them.
I guess the problem is that some people might end up being skipped over, losing candy hearts and kisses for the achievements or TOTs or whatever the holiday calls for. I can imagine it might also make some people feel they were purposely being skipped over even though that person might never have known they had done it, which can also create some tension between the users. I don't think I've been skipped over but I'm also not paying that much attention to who is below me.
I've noticed this too lately on the survival threads.
I think that is probably solely due to ping/latency and not really something that can be solved. The forums are laggy enough that there can be a fairly decent difference in time between 2 people who post at near exactly the same time to have their posts to reach the server.
I have noticed this on the kiss the user above boards, too.
Makes sense.
I just thought I'd bring it up. I can't see it being a big deal in practically any other topic other than the order important ones. Even if nothing can be done about maybe people will notice the topic and know that they weren't skipped on purpose or whatever.