There are two UMPs configured - one for internal use and one for external. The cabi_external probe is deployed in this environment. The cabi dashboards are visible from the internal UMP, but not from the external UMP.
UMP configured to use SSL but the external CABI server was not.
Enabled SSL on the external CABI server.
Change the cabi_url in the setup section of the cabi_external.cfg to use the secure HTTPS URL.