https://arstechnica.com/gadgets/2019/04/netflix-ends-airplay-support-on-ios-in-an-ongoing-souring-of-its-apple-relationship/

Netflix has confirmed that it no longer supports AirPlay, citing "technical limitations" with Apple's video-slinging feature. The reasoning isn't exactly about technical limitations that prevent Netflix from supporting the feature at all, though. Rather, Netflix has either chosen not to support it because the company can't control the user experience the way it wants to or because of bigger issues of competition and collaboration between the two companies.

AirPlay is a feature in Apple devices (and now in some third-party devices from partners like LG and Samsung) that allows streaming audio or video from one gadget to another over the local network. A few days ago, users began noticing that they could no longer use AirPlay in the iOS Netflix app, and MacRumors discovered that a support document on Netflix's website had been updated to say, "Airplay is no longer supported for use with Netflix due to technical limitations."