So I have a Note20 Ultra 5G and I was trying to mirror my screen to my smart Blu-ray player with a app but when it connects I get a grey screen. So I figured it had something to do with Knox so I downloaded SmartThings and tried that but still getting the grey screen. So now I have figured out it has nothing to do with the apps or the device. There is a problem with the Samsung Software that is causing the mirroring not to work. I think it either has to do with some sort of security issue or maybe a wireless transmission issue due to miscommunication with the software and the device. Also I made sure the device I'm trying to mirror to has been updated to the most recent Software. But any other ideas would help thank you.