When developing our XOGO Player app for LG consumer-version TVs recently, we discovered that LG does not allow apps like ours to cache and playback videos - only images and URLs. It's a limitation of the consumer version of WebOS (the commercial version is not affected). For that reason we're currently debating whether or not to remove the app from the consumer-version App Store at LG.
If video playback is a necessity for you we'd recommend picking up an external media player like a XOGO Mini Max or a Fire Stick 4K so you don't have these limitations. How many screens will you need to deploy? Please have a look at www.xogo.io/hardware for media player recommendations; or ask our team for help!