Why compute nodes and networks nodes fails to create all required tunnel endpoints when l2population is enabled?

Issue

• We have enabled l2population mechanism driver on neutron api server.

# grep l2popu  /etc/neutron/plugins/ml2/ml2_conf.ini
mechanism_drivers =openvswitch,l2population

• Enabled the same on all network nodes and compute nodes for ovs plugin.

# grep population /etc/neutron/plugins/openvswitch/ovs_neutron_plugin.ini 
l2_population=True

Then neutron-openvswitch-agent was restarted on all nodes, none of the node has created any vxlan tunnel endpoints under br-tun. When we disable l2population, all required vxlan endpoints are created when service is restarted. How can I solve this?