How to debug immediate disconnect

[Lootwig]

The airplay button opens a menu with the available devices on my wifi, but after selecting a target device, the video player only displays the "Airplay" logo on black background for a second or so, until returning to the in-browser video player.

From Youtube in the same browser, I can connect just fine, so I assume I need to adjust some configuration in my implementation - but without any error messages, I don't know where to start digging. Is there a way to get some feedback on what went wrong during the connection attempt?