Endian 3+Proxy, client ask for authentication

[Guest]

[xmatrix83]

Hello i configured Endian3 to do NAT and Proxy with the blacklist, it works well but I have a problem.
The proxy is configured as a transparent, In the client with windows 7,  the network icon displays "limited connection" despite this, it can browse internet correctly; it seems like there's a captive portal.
The big problem is with Android devices, because the behavior is the same but by default a wifi connection that seems limited, is turned off by the system after a few seconds.
What is the problem?
Whether this behavior was the default, there is some walkaround?

Regard.