So far have not found a solution to this.  I was however able to prove that this works for me by not having the DLT tables I am accessing to define my snapshot in the same pipeline.  The snapshot and the next_snapshot function I had to write worked and gave the resulting targe table I wanted.  It now just seems when i try to put it altogether it chokes.  Also, I've found that unless you have the scenario where you need to have your target table recognize that records are no longer in your source snapshot, you can just use the regular AUTO CDC (without snapshot), and it is much easier and you dont need to try to implement the problematic next_snapshot function.