This solution works for me in 4.19.
So basically
It works because Media Texture variable you created is linked (set as default) to The Media Texture assert you created, The Media Texture file is linked to the Media player assert that was linked by Media Player variable you created (set as default). & the Playlist assert is linked to the Media player variable via Open Playlist Index function call.
So when you call the event Playcutscene, by ‘L’ or ‘P’, The Cutscene Index was send to the playlist assert, & since Media Texture variable was linked through in the chain to Playlist, which I mentioned earlier, when you link Media Texture variable to apply at the white image, it works.
Also, I know someone who knows someone whose cousin knows someone, who knows his uncle works as a Janitor at Microsoft.
Note: I do have a small issue, which is the video doesn’t start smoothly with video often start with the other video in the playlist got cut, then the right one is placed. Not sure the problem is in the coding or the playlist. In any case, I waste many hours on this, so I need a break.