I had the same issue and noticed the tracker code being generated was missing the protocol. For example, in the tracker code I had something like this:
I changed it manually, and now see traffic data in the dashboard. Very annoying problem to have out of the box, but at least an easy fix. I tried to delve a bit deeper in the code to figure out what is causing it, but I gave up once I fixed it. I’m not sure if this is an issue that should have a bug report opened on it, or if it was something I messed up during configuration, but if it was my fault it was not obvious where I went astray.