It is working as expected. You are automatically logged in to GLUU and not asking for okta login because your okta session is still alive.
About correct logout procedure, you just need to perform oidc logout flow. we have [gluu logout docs available here](https://gluu.org/docs/gluu-server/4.4/admin-guide/openid-connect/#logout) and [here](https://gluu.org/docs/gluu-server/4.4/operation/logout/). First logout from gluu and seperate logout request to external provider(Note: logout request initiate from RP, not from Gluu UI logout button).
Mike, We have good docs about logout but not specific related to passport case so I'll add small logout docs in passport inbound section.