I am seeing two instances of strange curve behavior. Please see the below images. Black background are snips from TBC. White background are snips from Siteworks Emulator.
When I check the design in the Siteworks emulator, I get the following curve.
TBC Design shows correctly.
The design is type: Alignment. 1632 objects in design map, mainly alignment label entities.
After I first saw the issue I started running project cleanup prior to adding linework to the design. I also went back to the base file in Civil3D and made the linework into polylines, 3dpolylines, and line/arc and I get the same result for these two curves no matter what I try. From C3D I export the linework as DXF for import into TBC.
Any advice would be welcome.