I’m not the original poster, but I’m having this problem. I have a Roku Onn. Tv.
onn. Model 100071705
hardware g804x
serial number x01300P6J2MR
software version 13.0.0 build 24062-ct
it is in WiFi. The iPhone is an iPhone 14 up to date.
Same issue I have sound on YouTube screen sharing but not on other videos. Also, I sometimes have to do a YouTube screen share to even get screen sharing ti work at all. It seems to jumpstart it.