Watching Stan

Hi recently signed up for Stan and downloaded some programs on iPad 7 to watch off-line. Have an Apple Lightning digital av adapter that works well with a Panasonic TV ( no wifi or Internet needed) but from Stan we got only audio. Disconnected and reconnected AV adapter and HDMI cable which enabled both audio and visual from Stan but after each episode or movie the process has to be repeated. Now Netflix is playing up although it was working seamlessly before. Bit annoying - any idea how this can be fixed? Enquiry from Stan states programs off-line can be watched only through the device it was downloaded from - our disconnect/reconnect procedure proves otherwise. We are not big on technology but it’s hard to imagine the Adapter working with Netflix but not working with Stan. So if we signed up with Amazon would we need another adapter to watch off-line programs on a TV? Hardly user friendly and gets expensive. Any solid advice would be appreciated, cheers