I have the same problem sometimes. I've noticed it usually happens when trying to run them in Chrome. Have you tried a different browser?
I also tried edge and it did not work in that either. What browser would you recommend using to play it?
It's working for me in both Chrome and Safari. I have noticed though, that when I click on the start screen it sometimes takes 5-15 seconds to start. Its that issue happening for you too, or is it just not loading at all?