I generally agree it's an awful way to handle captcha, but I just want to drop a note about Discord to say that it's not always being buggy. Sometimes your accounts get caught in their automated login verification system, which is entirely different from HCaptcha. I would check your emails, including junk folders, just to be sure you haven't missed a notification from them. I did this once and it drove me nuts until I figured out that they wanted me to respond to a separate verification request.