The app is cloud based and finds the nearest working app server with the help of a DNS. If you get Error 503 or 504, please unplug your TV and Internet router for few minutes from Power. If you still get this problem, please put DNS server of 8.8.8.8 onto your TV, this way you will always get a working app server quickly and seamlessly.
We are constantly working on improving app infrastructure across all regions.
Thank you for understanding.
Yours faithfully, the Smart STB team.