When I bake bread in a loaf pan I am getting a very large hole at the top of the loaf that goes almost the full length of the loaf. It is happening with whole wheat bread and sourdough bread.

I mix the dough in a kitchen-aid mixer. The dough rises in a bowl in my dishwasher. I then form the loaf by rolling out the dough into a rectangle and rolling it up. I seal the seam and place the loaf in a loaf pan. The bread then proofs in my dishwasher. Then bake.

When I cut into the loaf the large hole along the top is there.

What am I doing wrong?

Jack