We have a known issue with login screens that are either a popup or a modal. While ReAn is able to successfully communicate with the backend in some cases it cannot display the drop down options.
Almost always, every site has a dedicated login page. That page typically shows the drop down. Try to avoid the popup if you can.
Use the down button. The options are present but just not visible. If you hit the down button you will be able to go through the options.
We will continue to look for ways to resolve this issue. So far we do not have any good leads. We will update this page, if anything changes.