Multitasking / Video

iOS/iPadOS will currently only “play” a single audio/video stream/source. As soon as your attempt to play a second, the first will pause/mute.

This behaviour appears to be by design.

Apple does invite submission of comments and feature requests via its Product Feedback portal. It there are features or functionality that you might like to see in a future release of iPadOS, this would be the appropriate channel through which to submit the request. For iPad and iPadOS:

Feedback - iPad - Apple

just tested with appletv app and vlc player they go into splitview but if one starts one the other pause