Answer
At the point this was raised, this was a known limitation/issue with custom pages specifically as command navigation targets in Aurena — the navigation-parameters attribute list wasn't populating for custom-page targets the way it does for standard pages, and the recommended path was to report it to R&D as a case for correction in an upcoming update rather than expecting a client-side configuration fix. Check current release notes or open a support case if you hit this on a recent track, since this may have since been corrected.