I had this quite a few times. And sometimes also not having a reaction when posting a message or clicking the like button or such actions (the bar indicating the forum is working scrolls horizontally, and scrolls some more, and abandons. Nothing happens. You have to do your action again)
It was worse on the recent past than what it is now (works quite fine for me right now). It was like the server was on some kind of load or under attack. I didn't say anything because I didn't know to what extent it was caused by the sh!tty VPN I'm using to access (so, problem on my side, actually). But if some other people are experiencing this things (or the screenshot you show, which I saw quite a few times), maybe there is something on the forum side.