I’ve found the issue.
The live function should be called with the slash at the beginning of the second parameter live(conn, "/sample/?jwt=some_payload"). Live View internally calls Plug.Conn.request_url which for this case returned "http://www.example.comsample/?jwt=some_payload" and then LiveView determined it is not a URL that is registered in the router.
I was actually surprised by the Plug.Conn.request_url result and created an issue for it Plug.Conn.request_url with request_path not starting with "/" · Issue #1058 · elixir-plug/plug · GitHub
