After WWDC2020 I can't open common YouTube in Safari on my MacBookPro 2020. I'm being redirected to m.youtube.com each time which looks just like on iPad or iPhone. The main problem is that I can't watch any video "because macOS doesn't recognize internet addresses starting with rtsp:" (I see this when I start any video). What to do about it?
UPD: I have macOS Catalina 10.15.5
UPD#2: I have a default user agent and changing it to any other doesn't help.