Problem with Configure SAML SSO for WiFi SSID over Captive Portal with Azure AD as IdP

Hello,

I try to configure SAML SSO for WiFi SSID over Captive Portal with Azure AD as IdP.

after connecting to the SSID I'm manage to get pup up browser with Azure Login page, after login I received in my Firefox web browser the message "Firewall Authentication Failed"

I'm using follow article:

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Configure-SAML-SSO-for-WiFi-SSID-over-Captive/ta-p/216020/ 

What I'm doing wrong ?

Please advice.

Thanks!