Http failures

Extensive testing has shown that sometimes it works, and sometimes it does not. When the tado app works, it works fine. However, the app mostly does not work.

My web browser typically displays the following: "Http failure response for 504 Gateway Timeout"

The app on my Android mobile phone often displays a blank page, or a spinning icon. displays "All Systems Operational". If all systems are operational, then why I am too often seeing: Http failure 504 Gateway Timeout?