I logged into the site and updated the akeeba software as well as Joomla.
When I go to the Configuration settings, the only boxes showing up for Dropbox are the folder and token. The Secret token and user ID are missing.
I tried uninstalling Akeeba and reinstalling it to try and clear the settings and make sure the files were all updated.
I am seeing the same issue. If I try to click on the Step 1 button, it takes me to the Dropbox screen, but nothing happens when I tell it to authenticate the site. The Akeeba screen never changes. I have several other sites that work just fine with the same information I thought was set up on this site.