When I attempt to cast video using airplay on my roku express 4k+ 3491x running 10.5.0 build 4167-CR i get nothing but a black screen. After about 4-5 seconds of black screen it boots me to the airplay settings menu most times. From some video sources I'll get audio but no video. Other times i'll just get nothing. Podcasts and music work great but video doesn't.
I also tried video casting apps like Web Video Caster and TV Cast. It's the same thing with all of them, I'll attempt to load a video source and it gets up to 99%, hangs, and throws an error on the iOS companion app.
I've already tried toggling all kinds of display/resolution and audio settings, my wifi networks match, i've tried resetting the roku, factory resetting the roku, toggling airplay settings and resetting, resetting my router, etc.
Side note: On my old roku express 3930x running 10.0.0 build 4209-AE Airplay and casting with the aforementioned apps works perfectly with video and all, so I know the problem is my new express 4k+ and not my phone. That being said I'm using an iPhone 7 running iOS 13.6.1
Side note 2: interestingly on the new express 4k that doesn't work, under airplay setting in the about section I can see the Airplay version number is 22.214.171.124 while the old express' version number is 126.96.36.199. Not sure if it's much of a smoking gun, just another difference I noticed. At a loss here
Hope there's something simple I'm missing, thanks for your time.
edit: just found out the exact same thing happens when I try to connect to roku as a display from Windows 10. The progress bar goes up to 99% and hangs.