In part, this is just my subsconscious' way of telling me I'm done working on a piece. (Not necessarily for good, but at least in that stretch of time.) It's somewhat related to the "muddle in the middle" — to misquote matociquala, call it "ennui at the end." That's a normal part of the psychology of writing.
In part, this is me becoming aware of my own style. Every writer has tics and tropes. That's a big component of auctorial voice. Some writers are so distinctive in this that you can tell who they are even without a byline — Hal Duncan, for example. Others go the opposite direction in being downright chameleonic — Robert Reed comes to mind. But the line between consistent style and repetition (let alone self-parody) is vague indeed.
Part of the satisfying reader experience is a comfortable familiarity. A Discworld book reads like a Discworld book, that's what draws us back again and again. But the dial is set differently for different readers, and for different (sub)genres. Perhaps the important aspect is whether the writer thinks they are repeating themself. So long as I like what I'm doing, and don't feel like I'm rewriting myself by parroting my own stylistic elements, I should be fine. I just need to duck the "ennui at the end." And remember to tell the difference.
How do you see the tension between consistency and novelty? Where you set the balance in your own work, or look for it in the work you read?