@leocg I think it's site wide at Yahoo. The Yahoo News page does the same thing now also. I discovered the other day that changing the user agent fixes it, as you stated.
Also, after Hulu.com recently redesigned their website, I get this: "Unsupported Browser. Use the latest versions of Chrome, Edge, Safari, or Firefox for the best Hulu experience.". However, changing the user agent to either Chrome or Firefox, the site works fine in Opera. Before the redesign, the site worked fine without the user agent switch.