Hmmm. This is beginning to sound like a Norton Security issue; at least the Youtube part. And that's where I'm out of my depth, 'cause I've not worked with Norton since they started selling firewalling software, frankly. Very hard for me to diagnose based on descriptions, esp. as I'm not certain what Norton does "under the hood" in terms of protecting and monitoring what you do on your browser(s).
If worse comes to worse, and it becomes too much of a nuisance, I suggest getting recommendations for a local service* to take it to (or to come to your house). It sounds like you might have deeper issues that can be fixed by a reboot and a couple of reinstalls, sadly. :(
*
NOT Geek Squad/Best Buy.