We have upgraded to Portal in our Staging Environment and looking to upgraded to portal in our Production Environment. Currently how our portal is configured is that the User and Group stores are configured to use Windows Authentication and we configured the SAML to allow logouts. However we cannot see or access the login and log out or change users in Portal. I have read the articles in ArcGIS FAQ: Why is the logout button missing in Portal for ArcGIS and ArcGIS Server? and setting Set advanced portal options—Portal for ArcGIS (10.6) | ArcGIS Enterprise and https://community.esri.com/ideas/14260 and still have not found anything out. Has anyone figured out a solution to this or has created a workaround to make it work.
You won't be able to use both Windows authentication AND SAML in your Portal.
If you want your users to be able to use their Windows credentials AND logout, I recommend only using SAML authentication as this will still leverage those accounts.