Error 419 when Attempting DiscourseConnect, JavaScript

I get this error when I try to sign up a new account with DiscourseConnect, error 419 in console.

My return URL looks like this: https://discourse.[myForum].com/session/sso_login?sso=bm9uY2UlM0RjOTU0OTIxMmE4YTY0MzEzNTI0M2M5MzY5NWE4YmI1ZiUyNmVtYWlsJTNEYm9uaG9tZWNhcmUlNDBnbWFpbC5jb20lMjZleHRlcm5hbF9pZCUzRDEyMzQ1JTI2dXNlcm5hbWUlM0RqYWNvYnByb3Zp&sig=7c3ec7f5cfb4d94a7316444cbab381a02e6ad87eb77cf409f2ef059053c0db2e

Anyone know what could be causing the login to time out?

Verbose does say that my nonce is incorrect, not exactly sure why that is the case.