I somehow managed to get a rx6900xt in my cart this morning. I made it all the way through checkout. To confirm order. And it wouldn't go thru. Eventually going to 503 timeout error page. I tried to refresh back into the checkout, and I got "You don't have permission to access "http://www.amd.com/en/support" on this server"
too much refresh (as a bot would do) get you banned.clear your cache/cookies and restart your browser