ps.ServiceIndex.instancesByPort[svcKey] = make(map[int][]*IstioEndpoint)
		}
		shards, ok := env.EndpointIndex.ShardsForService(string(s.Hostname), s.Attributes.Namespace)
		if ok {
			instancesByPort := shards.CopyEndpoints(portMap, ports)
			// Iterate over the instances and add them to the service index to avoid overiding the existing port instances.
			for port, instances := range instancesByPort {