Sounds more like an issue with your system/browser. Code generation appears synchronized properly enough on the device you use to get the code--or you couldn't log into the game/forums elsewhere.
Sounds like what you are using to access the website is having an issue processing the page/scripts properly. Have you tried it on another browser?... maybe Firefox? It works perfectly fine in Firefox on my Windows 8 machines as well as all my Android devices--it even works fine in Dolphin on those phones/tablets as well.
May simply be an encryption support issue. Might want to hit an SSL check site like howsmyssl.com to see how it is handling TLS1.2 (what the sign-in screen uses).
