The video player of our app is not the system's native player. Does it support picture-in-picture in live streaming scenarios?
Does Picture-in-Picture support non-native video player？
Afaik Netflix, hotspot and prime video are supporting picture-in-picture mode, idk if they use the native player, I recommend you to check that, I guess that'll help you and YT doesn't support it now, also appleTV+ uses the native player I guess, and I did check with some websites online as any online video plays in the native player works in picture-in-picture mode. So from my testing I can say that using the native player is the only way to support picture-in-picture mode. Do correct me If I'm wrong.