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.
This is a known defect that is not preset in the other versions. It is currently logged as CIVIL-32578 with the Autodesk Developers.
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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