Pipes are buggy
Random pipes or fittings are not exported
Revit 2020
(Twenty characters)
I suspect that may be the issue - 2020 and 2021 do not have the spread of API support that later versions do.
We increased the level of support for these across the Speckle connector.
If you’d like to confirm this, you can try upgrading to >—2022 and sending it to Speckle. If you don’t have access, we can see if this is indeed the problem.