Neutron router ports can not be deleted after migrating from previous Openstack releases to Juno

Issue

• While trying to delete the ports, the command succeeds - but the port is not deleted:

[root@controller ~]# neutron subnet-list
+--------------------------------------+-------------------+-----------------+------------------------------------------------+
| id                                   | name              | cidr            | allocation_pools                               |
+--------------------------------------+-------------------+-----------------+------------------------------------------------+
| 27ea300a-0403-4f6d-af4d-810dad6eff60 | internal-subnet-1 | 10.0.212.0/23   | {"start": "10.0.212.2", "end": "10.0.213.254"} |
| 3d11afb2-fa18-4daf-a885-fd84046aa61b | internal-subnet-2 | 10.0.62.0/23    | {"start": "10.0.62.4", "end": "10.0.63.254"}   |
| d07286bb-c1ad-49d5-8dd7-925b52a96a1c | dmz-2702          | 10.0.247.0/26   | {"start": "10.0.247.6", "end": "10.0.247.62"}  |
+--------------------------------------+-------------------+-----------------+------------------------------------------------+

[root@controller ~]# neutron port-show 9539eea4-02c5-4323-9d0b-0d6cec7c858b
+-----------------------+-------------------------------------------------------------------------------------+
| Field                 | Value                                                                               |
+-----------------------+-------------------------------------------------------------------------------------+
| admin_state_up        | True                                                                                |
| allowed_address_pairs |                                                                                     |
| device_id             |                                                                                     |
| device_owner          |                                                                                     |
| extra_dhcp_opts       |                                                                                     |
| fixed_ips             | {"subnet_id": "27ea300a-0403-4f6d-af4d-810dad6eff60", "ip_address": "10.0.102.6"}   |
| id                    | 9539eea4-02c5-4323-9d0b-0d6cec7c858b                                                |
| mac_address           | fa:xx:3e:c6:xx:xx                                                                   |
| name                  | blocked-7                                                                           |
| network_id            | 948e10ac-ac18-47e4-b362-176aaa7feb19                                                |
| security_groups       | c663210c-0a0a-4336-a522-aa9941f9dccf                                                |
| status                | DOWN                                                                                |
| tenant_id             | c1341525a8b241ad93adaafd9cae2b1d                                                    |
+-----------------------+-------------------------------------------------------------------------------------+
[root@rtp1-cos-mgmt-001 ~]# neutron port-delete 9539eea4-02c5-4323-9d0b-0d6cec7c858b
Deleted port: 9539eea4-02c5-4323-9d0b-0d6cec7c858b
[root@rtp1-cos-mgmt-001 ~]# neutron port-show 9539eea4-02c5-4323-9d0b-0d6cec7c858b
+-----------------------+-------------------------------------------------------------------------------------+
| Field                 | Value                                                                               |
+-----------------------+-------------------------------------------------------------------------------------+
| admin_state_up        | True                                                                                |
| allowed_address_pairs |                                                                                     |
| device_id             |                                                                                     |
| device_owner          |                                                                                     |
| extra_dhcp_opts       |                                                                                     |
| fixed_ips             | {"subnet_id": "27ea300a-0403-4f6d-af4d-810dad6eff60", "ip_address": "10.0.102.6"} |
| id                    | 9539eea4-02c5-4323-9d0b-0d6cec7c858b                                                |
| mac_address           | fa:xx:3e:c6:xx:xx                                                                   |
| name                  | blocked-7                                                                           |
| network_id            | 948e10ac-ac18-47e4-b362-176aaa7feb19                                                |
| security_groups       | c663210c-0a0a-4336-a522-aa9941f9dccf                                                |
| status                | DOWN                                                                                |
| tenant_id             | c1341525a8b241ad93adaafd9cae2b1d                                                    |
+-----------------------+-------------------------------------------------------------------------------------+

[root@rtp1-cos-mgmt-001 ~]# sleep 30; !!
sleep 30; neutron port-show 9539eea4-02c5-4323-9d0b-0d6cec7c858b
+-----------------------+-------------------------------------------------------------------------------------+
| Field                 | Value                                                                               |
+-----------------------+-------------------------------------------------------------------------------------+
| admin_state_up        | True                                                                                |
| allowed_address_pairs |                                                                                     |
| device_id             |                                                                                     |
| device_owner          |                                                                                     |
| extra_dhcp_opts       |                                                                                     |
| fixed_ips             | {"subnet_id": "27ea300a-0403-4f6d-af4d-810dad6eff60", "ip_address": "10.0.102.6"}   |
| id                    | 9539eea4-02c5-4323-9d0b-0d6cec7c858b                                                |
| mac_address           | fa:xx:3e:c6:xx:xx                                                                   |
| name                  | blocked-7                                                                           |
| network_id            | 948e10ac-ac18-47e4-b362-176aaa7feb19                                                |
| security_groups       | c663210c-0a0a-4336-a522-aa9941f9dccf                                                |
| status                | DOWN                                                                                |
| tenant_id             | c1341525a8b241ad93adaafd9cae2b1d                                                    |
+-----------------------+-------------------------------------------------------------------------------------+