When onboarding stacks, you see one entry for each slot when first adding serial numbers. After the stack is configured and operational, all slots will consolidate into a single stack object in ExtremeCloud IQ. It can take up to 15 minutes for the slots to consolidate and for ExtremeCloud IQ to recognize all slots as online. You might see a red icon in ExtremeCloud IQ if slots are offline or have not yet onboarded.
If slots continue to show offline, ensure that all slots are powered and that stacking connections are up and active. CLI verification might be needed if issues persist.