AGOL Group sharing using deployment of VertiGIS Studio with AGOL

We understand it is possible to use Portal groups to share VertiGIS Studio apps.    However this does not apply if your deployment architecture consists of VertiGIS Studio Apps and AGOL.   The issue is;  we can invite and add and outside organization to a group where VertiGIS apps are shared, but those users cannot access login to the VertiGIS apps. They can see and attempt to login to the app, but receive error messages of “ Member is not part of the organization”.  Some dialogue on this subject was documented with VertiGIS helpdesk number 155547.   We would love to have this functionality as we are now forced to replicated specific functions in Experience builder as it can be shared as expected in AGOL Groups.