Guest SSID on fortigate (FortiAP) with external captive portal authentication on clearPass issue

Hi guys,

I am configuring a Guest SSID in tunnel mode on fortigate (FortiAP) with external captive portal authentication on aruba clearpass.

The redirection to the captive portal works correctly and when I log in with a user and password, Fortigate transmits the credentials to ClearPass which authenticates the user and correctly returns an Access-Accept.

However, the problem is that Fortigate does not authorize the user so it always remains on the captive portal page.

Anybody have an idea about the cause of this issue ?

Best regards