SSO not working correctly with PBI

Hi All,

We have an internal portal where we are displaying a PBI report, and login to the portal is through the org SSO. When we are logging into the application PBI will still ask us to sign-in again, & when we click on Sign-in - it redirects directly to the portal page as sign-in information is already avilable in the current browser session, sign-in is compleetd & report loads. What I do not understand is this behavious shold not occur as in SP same SSO login works fine for the PBI report as well but in this portal it is not following the same.

Has anybody faced similar issue ?

Note - Link for PBI report is being generated from PBI service - iframe.

Thanks,

Max