Captive Portal of APM/SWG Forward Proxy can not redirect to original URL

Hi Gurus

 

I configured APM/SWG Forward Proxy with Captive Portal to authenticate SAML. Every things is OK but when Browser change back to Captive Portal (as SAML SP), it display the blank page (https://sp.f5test.com/saml/sp/profile/post/acs) but no redirect to original URL.

 

Thanks

 

Phong