Have you followed the below instructions? You will need to change the H9000 clock source depending on the configuration:

To sync the H9000 to Dante, set the H9000’s clock source to “Exp A/B/C (Dante)”, and uncheck “Enable Sync To External” for the Dante card in Dante Controller.

To sync Dante to the H9000, set the H9000’s clock source to “Int {sample rate}”, and check “Enable Sync To External” for the Dante card in Dante Controller.