Hello Felipe, could you check if you are not able to get the web auth login page from different web browsers? just open the browser an go to http://1.2.3.4/login.html
Hello Mauro, try to identify if the issue is on the client-side or the AP side.
From the WLC we should be able to see the new reassociation request from the client to the new AP, the authentication (PSK or 802.1x) and the 4-way handshake. to get that...