Trust your subconscious.
I would say, do not stop writing, do not break your habit of writing every day. Just stop writing THAT. Do some other writerly stuff, on this project or a different one.
When I find I am stalling in a story, I also find that this is often because my subconscious mind knows there is something wrong with it, and perhaps some vague feeling that something is out of kilter is sapping your energy to write because it would be a waste of time. Check that out: Take your writing time to go back to the beginning, read and/or edit what you have done, looking for a plot hole. A character doing something out of character. Try to find out what is wrong with your story.
A common problem for outliners is cardboard characters that begin to feel unnatural, as they are given the unplanned part of the story (dialogue, emotional reactions, individual actions, dress, thoughts, feelings) they become fleshed out in the author's mind, but increasingly (as the book progresses) they don't really fit the role prescribed for them in the outline. They have veered away, and if they DO the things they are required to do, it feels forced.
Outliners can often see this in the span of half a book: The character on page 200 seems and feels like a different person than when they were introduced on page 1, not in the sense of having learned lessons or suffered heartbreaks, but the character on page 1 is inconsistent with the character on page 200. Maybe where the page-200 version would crack a joke or be irritated the page-1 version does nothing (or vice versa).
Go back. read, revise, look for problems, see if you could improve anything, now that you have more experience writing and with the characters. Even if you do nothing, it will reload the story in your head and perhaps invigorate you.
Another issue for outliners is gratification too long delayed. Fortunately, you have an outline: Instead of writing the scene you need now, skip it. Write the one after it, and come back to it. Find a fight later and plan the choreography. Write notes on later scenes.
The biggest thing for me is to seriously consider that this may not be simple fatigue demanding a break, this may be your subconscious telling you there is something amiss in your story, and it doesn't want to write another word until you fix it. Actively look for it. Because taking a break doesn't fix the problem, and you may end up abandoning the work.