I am having an issue with a cut extrude.  When I cut the geometry through the part, I am left with an "open" cut instead of a surface.  Like the base extrude was a shell.  But I don't see where that is possible.  As you can see from the attached model, the cut on the bottom is allowing me to see into the inside of the extrude but I shouldn't see anything.  I had the same issue with the gray cut extrude, but by extending the geometry past the extrude, it fixed the issue.  I have tried that on this bottom cut, but it doesn't fix the issue.

Any ideas?

Thanks,

Bob