Join multiple spans (grpc)

I created a small sample application to try out dapr and decided to go the grpc route, while it seems a bit more unpolished it works great, so great work and thank you!

The issue I have is that while all my spans correctly shows up in zipkin they always just show one interaction. Like from Client -> Server or Server -> Access and not the full call chain which is Client -> Server -> Access. However it shows up correctly in the dependencies tab.

So my question is, how to I join the spans together?