This website (support.discord.com) breaks if third party cookies are disabled, with unhelpful error message

I normally keep "third party cookies" disabled in my Chrome browser for privacy reasons. I have discovered if you attempt to log into this site (support.discord.com) with third party cookies disabled, logging in is blocked with the cryptic message "invalid authenticity token". If I whitelist third party cookies for support.discord.com, I can log in to this site just fine.

Expected behavior: If your website requires third party cookies that is fine, however, the error message is extremely unhelpful. I wasted a lot of time trying to figure out what it wanted. A better error message would include text like "If you have third party cookies disabled, try adding an exception for this site."

Because I have now disabled third party cookies, this no longer affects me, but it should be fixed so it doesn't mess up the next person.

I filed a bug as a trouble ticket with a screenshot, but they closed it and said to file feedback here. Of course, no one affected by this bug will be able to vote this feedback post up, because by definition they cannot log in and don't know why...!