So after some testing I’ve found that when adding any new generator devices inside a macro and then connecting them to devices, the connection is dotted and the top left mini preview shows black for the whole chain. It’s not actually broken though, it has no warnings and builds fine, I can view the results of the chain in the 3D View just fine. If I save the project and reopen it then the mini previews work and there are solid black connections, as it should have been in the beginning.
Edit: meant to label 3.0.Dev1, oh well