I don't know how else to explain it but sometimes when I'm browsing the forums, comments from different threads end up in others. For example, I was looking at a thread in the #Offtopic, lets call this thread A, about Trump's handshake. As I was scrolling down I noticed that I had posted a comment I don't remember posting. I noticed the comment was actually posted in a different thread, thread B, about reaching 500 replies. Every comment after my comment in thread A was from thread B. I've noticed this a few times. I apologize if this issue has already been addressed, I did a quick scan on the forums and didn't see anything about it though.