Welcome to the ODK forum, @Fuller! We're glad you're here. When you get a chance, please introduce yourself here. I'd also encourage you to add a real picture as your avatar because it helps build community!
We've very recently updated the AWS installation guide and solved some issues with the login process. Could you confirm that you've installed Aggregate v2.0.2 following the current guide at https://docs.opendatakit.org/aggregate-aws, please?
Also, could you describe how it fails when you try to log in? Does it reject the password? Does it timeout? Any other effects?