neutronvpn:networkMaps update failed when add the second subnet under network

Step1: Create network on openstack;

Step2: Create the first subnet under the network, Get networkMaps information successful：http://localhost:8181/restconf/config/neutronvpn:networkMaps;

Step3:Create the second subnet under the network, Get networkMaps, but there is no information for the second subnet, and karaf.log show as follow:

2019-11-19T07:26:59,010 | ERROR | org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.subnets.rev150712.subnets.attributes.subnets.Subnet_AsyncDataTreeChangeListenerBase-DataTreeChangeHandler-0 | NeutronSubnetChangeListener | 371 - org.opendaylight.netvirt.neutronvpn-impl - 0.10.0.SNAPSHOT | Create subnet-network mapping failed for subnet 4ac170fc-145c-4a6e-916f-839fb3fa0aab network cce22ec3-6a1f-4553-997f-80bdc5e04ec9