Nginx reverse proxy issue with authentication

I’m not on the latest HA so I can’t test the language settings, but did you add all of the proxy related stuff as noted on this page?

Also, for html5 push notifications, /manifest.json can’t be behind basic auth when enabling/disabling push notifications for a device. On my own setup both /manifest.json and /api/notify.html5/callback are not behind basic_auth for full html5 push notification functionality.