@nik This was the board I tested it on. 😆 I'm not sure if @julian can shed some light on this as something isn't right with your experience and I'm not sure what would cause these things to happen. It's not your build of NodeBB, it's not one browser or the other as it happens on both Desktop & Mobile, the only thing left is your internet connection, but I don't know whether xhr-polling or websocket issues would cause it.
Is it possible to disable the @ mention on clicking reply? I share the opposite opinion as the thread author here: if I'm replying to someone, an @ mention just seems redundant: they're already going to receive a notification for that reply, right?