I have an existing site I need to point to a new GitHub repo, as if moved the site to a GitHub org.  having removed the original repo from the site and tried to connect the new one, I get the success notification but the repo doesn’t appear to be connected. The GitHub link into e site cover panel still indicates the original repo and the settings page shows no connection.
TL;DR
 Developer needs to point their existing site to a new GitHub repo after moving it to a GitHub org. Despite receiving a success notification, the repo does not appear to be connected. The GitHub link in the site's control panel still shows the original repo and the settings page shows no connection.