If you want your Mirantis Secure Registry (MSR) to use session-based authentication cookies that expire when you close your browser, toggle Disable persistent cookies.
You may need to disable Single Sign-On (SSO). From the MSR web UI in a Chrome browser, right-click on any page and click Inspect. With the Developer Tools open, select Application > Storage > Cookies > https://<msr-external-url>. Verify that the cookies has Session as the setting for Expires / Max-Age.