CodeGuru not loading the list of private GitHub repositories

Trying to associate GitHub account & repo with CodeGuru. In the "Associate repository and create a code review" form, I am able to connect to a GitHub repo of which I am the admin/owner. The auth with GitHub goes through fine. However after connecting with GitHub account, the Repository location fails to update and show the list of available private GitHub repos.

I am able to use the same account with CodeBuild/Codepipeline w/o any issues and they all are able to find the private GitHub repo. Looking at the docs on https://docs.aws.amazon.com/codeguru/latest/reviewer-ug/create-github-association.html can't see anything different. How do I get CodeGuru to find the GitHub repos?