Did you find a solution for this? I have the same question.

I'm having the exact same issue. Online product is set to "Active" with "Online Store" Sales channel included in multiple collections that are live on the store and can only see a buggy "Preview" of the product page. When trying to navigate to the pr...

Looks like that was the issue. I've upgraded now to Monterey and it worked. Thank you!

I'm having the same issue as well. Anybody know what might be causing this? Maybe it's Catalina?