A few macOS betas ago, a bunch of sites started failing to play video for me in Safari. Disney+, Netflix, YouTube and some other sites will sit at a black screen for a few seconds and then give me an error. Sometimes it works, sometimes it doesn't. Sometimes certain videos will reliably fail while others reliably work fine. I thought this was related to Safari's autoplay protections, but I tried giving permission to autoplay all videos and that doesn't seem to change anything. Not sure if that fits the definition of a Snow Leopard update. If so, Apple needs at least a few more Snow Leopard updates at this rate. I'd also like to see them fix the issue where Liquid Glass uses a downscaled background image even at the most transparent setting. (Except for Siri AI which they seem to have added a special exception for, exactly because the downscaling is super ugly)

Hey sorry to be the debugging guy in the comments, but maybe your network issues could be related to iCloud relay? I’ve had similar issues