Cut volume difference

HI

I want to calculate the cut volume for the foundations of a bridge pillars. My workflow is the following one: 

1. Draw the shape of the foundation

2. Apply a height profile

3. Apply a linear template (in this case a Cut with a 2:1 slope)

After this steps I used corridor components to find the cut volume and i got a value of 9615 ***. When I used the Analyze volumes tool I got a cut Volume of 22545CuM. I tend to believe that the method using the Analyze Volumes is more correct, but why such a big difference?

Thank you in advance