Look at the generated sources, there is no http://local.website.com:4000/. Your browser only augments it because your href is relative. Use a schema and it work as you expect.
I am adding a third host/domain arg for a multi site cross domain linking solution
I saw dailydrip do some vids on extending actions and routes for a 3rd arg or I could use the host in the router, but I am exploring Forward in router.ex