On Demand shows not free?

I'm curious why suddenly an NBC show wants to charge me to watch episodes on demand, when this has never happened before. I am trying to view the Oct. 27 episodes of This Is Us, but it's saying they cost money per episode/per season. 

I can watch any previous season's episodes just fine, and could always watch that week's new episode the day after it aired. 

I'm curious if this is in error or if some policy has changed that we weren't made aware of.