It looks extremely behind, and is probably stunted in growth. Those will not be hatching anytime soon. There's just no way they can catch up on that growth. Leave the turner on and keep incubating them.
This is the problem, as others said. If you can't get the temp correct fast you're going to lose them all. Your incubator is like my old one, I had great hatches in it too, and then it went berserk and couldn't hold temp at all.
That's when I had to get a new one. It's better to just start out with a good incubator.
That does look like multiple yolks to me.
And the duckling looks super behind, as others said.