Andrew, as far as I'm aware, this is very normal. You shouldn't try to force both halves together, as they could become stuck or damaged, potentially leading to catastrophic failure. If there's more than a couple of centimeters of 'naked' rod blank sticking out of the join, there might be something wrong with the fit. Otherwise, I don't think there's anything to be worried about. I'm sure some of our most experienced members will weigh in on this topic, but I'm pretty confident not all two-piece rods were meant to sit flush all the time.