I just joined and went to reply to a thread. It looked like it went through but when I went back to the thread it didn't show up so I tried to post again, at which point I was told I was making a duplicate post (I had c/p my initial reply). I gave it some time and the reply still isn't showing, but it says that I'm subscribed to the thread.
I then went to reply to another thread on another board here and was told I needed to wait at least 60 seconds before posting again (meanwhile it had been several minutes since I last posted), and to wait another 45 seconds before trying to post. When I posted this reply it, too, is unable to be seen.