Peoplesoft screens in an iFrame

Has anyone successfully integrated Peoplesoft screens or navigation via an iFrame in a third party app like Liferay or uPortal?

We are trying to integrate Liferay Portal as a web front end and consume some of the PeopleSoft screens in an iFrame portlet. Both the Liferay Portal and Peoplsoft systems are on different top level domains. We are using Oracle Single Sign On on bot the applications. We have a couple of issues with this.

The screens display in the iFrame - however, the JavaScript on the PeopleSoft does not execute and keeps spinning. In Chrome devtools console, there is the following error:

Uncaught TypeError: Cannot read property 'getStoredData' of undefinedPT_PAGESCRIPT_win0_MIN_1.jsp

If not already signed in to the PeopleSoft system via SSO - the Login page pops out of the iFrame on IE browsers. To clarify based on comments below, the SSO happens for the first app like Liferay, however the user didnot try to go the second app PeopleSoft yet. So the SSO cookies for the second app (PeopleSoft) are not yet in the session. So when we access the page with the iFrame containing the Peoplesoft page, it pops out of the frame in IE trying to establish SSO session and cookies with PeopleSoft.

Has anyone been able to solve any of these issues?

Any insight would be much appreciated. I can provide more details if needed.

Thanks!

Edited for clarification based on comments below.

We have been able to resolve the above 2 issues.

First, we created a new instance of the portal in the same parent domain as the PeopleSoft domain and ensured both were using SSL so the protocol matched. This resolved the cross domain JS errors
Second, we changed our Oracle IdM SSO login flow to always redirect to a new PeopleSoft PIA which redirects back to Liferay's original URL. This ensures there is a valid PeopleSoft session and prevents iFrame popouts along with other integration issues. There is a lot of changes and work done by our team on this around related use cases(deep links, session timeouts) and flows. I'd be happy to post more details if anyone is proceeding down the same path.

Thanks for all the comments which helped us dig in the right direction. We also got feedback from other Liferay and PeoplesSoft customers who followed similar approaches.