Issue:
Civil 3D 2019.2 or 2019.3 will not draw pipes and structures correctly (in elevation view) when it's toggled to start at the downstream structure and work the upstream direction.
Causes:
This is a known defect that is not preset in the other versions. It is currently logged as CIVIL-32578 with the Autodesk Developers.
Solution:
If this functionality is required, then your best bet is to use 2018 or 2020 to product the correct gravity network layout.
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