Hi Razhsnm,
your configuration is ok. With that configuration registered user will be recongized and welcome portal provides user name and password field already filled in. Then user will only have to click on Start Browsing/Log in button.
Is it possible that your customer think that they will be automatically logged in? If yes, sorry but even if you configure the device recognition as you did. user must click at least a button in order to be able to surf. It's not possible to avoid clicking the Start Browsing/Log in button.
Best Regards.