I have the first two Sanctum skies - Blue and Moons - but I keep getting offered the blue one again as a reward even though I can't select it. I am never offered the third. I have three grounds, two of every item that can go on top of furniture and three of some, and one of each of three furnitures.
Also, I know that I am always talking about hammers, but are you sure that you didn't do something to make them stop spawning when you made them work in Expansion? Before that update, I got four hammers in two or three days, since the update I have had none.