It is probably just tired from the hard work. Let it be for now. I have never had an egg zip nicely that didn't finish on their own when they were ready.
After they internally pip they will start chirping. Not all of them chirp before external pipping but I find a lot do, especially when they have friends chirping. One chirps and the others reply.
If you don't have pipping by day 23 I would candle again. Patience is the name of the game when it comes to hatching. I know it is hard to wait but the more you mess with the egg during hatching the worse of an outcome they can have.