Cannot play video. Connected display not supported
I've been using my iPhone 6 Plus connected to my tv using a lightning digital AV adaptor (which I got from the Apple Store) to watch Netflix, Hulu, and HBO Now. For the past week or two I've only be able to watch Hulu. HBO Now is just a black screen with the sound coming in perfectly. Netflix plays a black screen for 10-30 seconds then gives me the message "cannot play video. Connected display not supported" it worked fine for years but all of a sudden it wouldn't. I bought a new adaptor thinking that might be the problem but it wasn't. Any ideas on why this is happening or ways to fix it?
iPhone 6 Plus, iOS 9.3.2, Netflix is updated