Tried grabbing the Tonight Show with Johnny Carson from the Roku channel. It has a dozen or so seasons. When you first click on the show it appears streamfab starts to open each season to scrape the episodes and you can see the page refreshing between each load.
The issue appears to be this rapid succession of loading appears to trigger some sort of cloud flare protection that Roku has, guessing to prevent bots, and it goes to a CF error page. I’ve tried this on 2 different systems with 2 different isps.