I think this is a deliberate behaviour by Github to control the URL showed in the URL bar.
If you look at the network traces in dev tools, there is a GET request to https://github.com/gorhill?direction=desc&sort=updated&tab=stars
I don't plan to go through their JS line by line, but there's a range of history.pushState() calls, some to do with tracking URL changes. I assume that they are doing this to create nice vanity URLs. That other browsers (including Firefox) do the same make me think this is "by design" behaviour.