Please help me I made the yeast doughnuts. The first time they came out beautiful and risen . But after that they haven't worked for me . After I shape them I put them in a warm oven to prove them but as soon as I take them out of the oven and go to pick them up they go as flat as pancakes . The rise isn't as good as it was the first time either . Please help me . I love baking and since they haven't been working it is really bringing me down .