Re: Storming the Castle
The continues gameplay activity (which involved making a huge boulder swing towards the castle door, hitting it.) just would never cut to the cut scene.
My fix: I downloaded and re-played the chapter on my other PS4 which is a Pro. It still did the same thing. Would not cut to the cutscene. So I re-played the chapter in LOCAL mode. And not ONLINE. Maneuvering two controllers at the same time. And it worked! Then I uploaded the Saved Data back on the original PS4 Slim and continued the game with my friend.
I'm guessing the issue was with the Friend's Pass.