Writing a duology

I’m currently working on a duology, and I’m getting stuck on Book 2. (Finished Book 1 about 2 months ago, took a break to outline, and am coming back now.) I wrote the first several chapters no problem, but I’m starting to feel bored with the story. It’s fully outlined, so it’s not an issue with plot or characters. I’m not sure whether I need to be more self-disciplined and just sit down and finish it, or if it’d be wiser to take a break, work on something else for a bit (I have all sorts of short story/novella ideas churning around in my head…), and come back refreshed. Thoughts on that?