Apple TV+ doesn't work in my web browsers.

When I log in to Apple tv+ using my Chrome or Safari browser I get the page with all the films etc but when I click on one to see it, I get a message that there was an error and to try again later. Then a black screen with nothing on it. This both in OS10.11.6 and in OS10.13. I have no problem watching content on Netflix, Amazon Prime, Disney+ or Canal+.

When I open the Apple TV app on my iPhone XR using the latest iOS it works fine. But I would rather watch films on my monitor's large screen than on the iPhone.