I'm having trouble with the Secure Guest User setting change. Our community was setup by a consultant we no longer work with. My understand is we have a Guest Community User which creates all Community Portal users. When a Community Portal User is created, they pass through a generic Household account before their own contact and household account are created. However, when we turn on the Secure Guest User setting and a Community Portal User is created, they get stuck in the generic Household account and need to be manually removed and split into their own household.

I'm trying to utilize the Guest User Access report app to help guide what I should be doing to check our readiness for this setting change, however I can't get the URL to go to the report. Instead it just goes to our login/registration page. This is the step I'm referring to in the instructions:

"From a private browsing session, or one that you are not logged into the org where the package is installed, navigate to https://[communityDomain]/[communityPrefix]/apex/guar__guestaccessreport running as Guest User"

Additionally, when I look into creating a Sharing Rule to ensure there is no issue with enabling this setting, I can't figure out how I would disseminate it to our custom External Identity Profile users. They aren't (and moving forward can't be) in a public group, they have no Role, and when I try to choose Portal user role, I see a list of individuals. 

Can anyone help me? Happy to grant login access or provide more details! In the short term I know we can revert the setting update but it sounds like that won't be an option with the Summer '20 release.