Yes we've tried it with several different Android devices, older and newer, and it is happening on all of them so far. The auth plugin is a custom one for Shibboleth. The site is set up to open the login in the browser, the user authenticates and then is supposed to be redirected back to the Moodle site which then sends them back to the app. It gets hung after authentication when redirecting back to the site. These steps work properly for iOS, but I think there is a difference with the redirection back to the app in iOS because it has the prompt to open in the app.