FortiSASE
FortiSASE delivers both a consistent security posture and an optimal user experience for users working from anywhere. Secure your hybrid workforce by closing security gaps, plus simplify operations.
kyozloveyou_FTNT
Article Id 288648
Description This article describes how SAML URL is required to be exempt when not using known SAML like Okta, Azure and etc.
Scope FortiSASE, SWG SSO.
Solution

If hosting SAML in public:

 

saml.png

 

nslookup saml.lab-kl.XXXXXX.YYYY
Server: one.one.one.one
Address: 1.1.1.1

Non-authoritative answer:
Name:UUUUU.XXXXXX.com
Address: 180.72.X.X <----- Public IP is resolved for SAML URL.
Aliases: saml.lab-kl.XXXXXX.com

 

Follow setting is required for proxy setting:

 

proxy.png

 

Result:

 

loginpage1.png

 

login2.png