2019 D5, and I'm able to play 2 separate videos on my 2 rear entertainment screens just fine. Trying to figure out how to make both screens play the same video. This worked fine in my Range Rover and I'm baffled. Infotainment is the very latest as of today's date, so I'm not on an old system. Any hacks or secret buttons I'm missing? User manuals are useless. Ironically the InGuide app shows only 2017, 2018 and 2020, doesn't even show the 2019 year manuals LOL.

 

While I still can't do one usb video across both rear screens, I was able to get a Chromecast plugged in, connected to my vehicle wifi, and have both screens set to the same HDMI. I can than play anything from my phone to both rear screens. Not ideal, would like to find how to play USB Video to both screens...