have a 58PUS7304 android tv. It came with backdrop installed. I went to Settings > Android Settings > Device Preferences > Screen saver and enabled backdrop and set the “When to start” to 5 min. After 5 minutes of idling nothing happens. Am I dumb or is there a catch to this?
Maybe there might be some problem with the screensaver app, so go to apps and then try clearing the data & force stop the Backdrop app.. if it doesn't works, try installing Another Screensaver app. I recommend you to try "Aerial Views".. even if that doesn't work then Factory reset your TV.
If nothing works, there maybe some problem with the Android TV operating system and idk any other method to fix :P (Above methods should definitely work)