I have implemented the customer self-service portal add-on for our Dynamics 365 CRM Online, and I have a custom OpenId Connect external identity provider (Identity Server) configured for authentication. That identity provider is used for some of our other services, so a customer can log in elsewhere and then come to the Customer Self-Service site and sign-in with the same provider, however if the customer logs out at one of the other sites/services, they are not logged out of the Customer Self-Service portal site. I would like to know how (if possible) to configure the portal to allow for a single log out to clear out all sessions for that user. I know OpenId Connect supports a sort of back channel logout and our custom identity provider is doing that, but it is not working for the portal. Is there a signout endpoint that needs to be configured or some site setting in the portal for this? I have read through the documentation and came across the Authentication/OpenIdConnect/[provider]/ExternalLogoutEnabled site setting. This appears to work in the opposite way I was hoping for, with this setting enabled I am logged out of other sites/services when I log out of the portal, but I still have the portal session if I log out from one of those other sites. Any help is much appreciated.