Are you trying to use your steam login to sign in to it? If yes, then please create a Frontier account at https://www.frontierstore.net/customer/account/create/ and use your frontier account login information and it would work fine. There have been issues with using Steam login details.
You also might want to check if you have a browser plugin that limits the Issue Tracker website from functioning normally. I know that certain privacy plugins such as Privacy Badger blocks the Issue Tracker from loading content.