Hi there! Thank you for the detailed information and troubleshooting you've already done. I like watching my videos in surround sound too, so I can relate to the inconvenience this has caused. Let's get this fixed. Based on what you've described, it sounds like the issue is isolated to the YouTube and Paramount+ apps on the X1 box, since Netflix, Peacock, Max, Disney+, and your other devices are all properly outputting 5.1 surround sound. To help us investigate further, can you confirm whether this behavior started recently or if it has always occurred with these two apps? Also, are you seeing the issue on multiple programs within YouTube and Paramount+, or only with specific content? Since you've already tested the same content on your TV's native apps and Apple TV and confirmed 5.1 audio is working there, that information will be very helpful in determining whether we're dealing with an app-specific issue on the X1 platform.