iPhones and iPads can be connected to additional screens such as televisions or monitors via HDMI, provided the adapter used passes Apple standards. This allows users to enjoy content such as playing games or watching videos on a larger screen.
But since last year, Apple has started discontinuing AirPlay support on older model Apple TV devices. This issue appears not to stop at AirPlay alone, as an iPhone or iPad using iOS 16 or iPadOS 16 also cannot play DRM content if the device is connected with an HDMI adapter.
This means, if the iPad is connected to a monitor – Netflix, Prime Video, Apple TV+ and others cannot play video and will only display a black screen with audio only. Playing YouTube videos seems to be no problem. There is no workaround unless the user's iPhone or iPad is still running iOS 15.
What users can do is, use the AirPlay 2 broadcast feature. Most televisions and smart monitors already support this feature. Even if you use a Google TV dongle no matter what brand, you can usually play Netflix from the device directly to a TV/monitor with a Google TV/Android TV dongle, TV box set and the like.