API does not return labels for entities

I am trying to retrieve the labels of all of our sensu enties via the api.

When I send a request to /api/core/v2/namespaces/default/entities/

I can see key for labels in the metadata section but it is empty for all entities, even though all of of entities have labels. This is a similar story when I pull information for a specific entity.

Just wondering if anybody has any ideas please?