The oven temperature was low and the heating time excessive. However, the range display showed the requested 400F, even though the oven was really 250F. Because the oven displayed an inaccurate temperature, I ordered an oven sensor, a heating element, and a terminal block.
Replacing the heating element fixed the problem. The element I received was the same shape and size, but the supports were not the same. However, I think it must have been a design change after mine was manufactured because it looked like the original mounting brackets were allowing the heating element to hit the oven floor. The new element had a bracket to prevent it.