Imported Channels are not properly assigned to the send channel I also imported from a previous project with similar channel setup.
How to reproduce:
Create project with an instrument and a FX channel. Assign a send to the created FX channel and save project.
Make a new project, import instrument and FX channel
You will notice that no audio is transferred to the FX channel despite it being displayed as routed and active
Only reassigning that send will make it work again
Here is a video of the problem:
Hope this helps find your bug!