GBP: PTG delete at times not cleaning neutron resources

All GBP Objects being deleted, yet some of the neutron resources are left behind, precisely net,subnet, dhcp-ports.

The cleanup-script which I have used to delete the GBP objects in the reverse order of their creation, results in deletion of all GBP objects.

I am yet to determine the exact work-flow by which this issue manifests

Look at the logs below:
<<Referring from linux history the GBP PTG "J", which was created and deleted too..>>

 1795 gbp policy-target-group-create J --l2-policy 526ba7f3-7bfa-4eb5-adb7-b0c36449797a
 1811 gbp policy-target-group-show J
 1826 neutron subnet-show ptg_J
 1934 gbp policy-target-group-show J
 1936 gbp policy-target-group-delete J

<<Referring to non-existence of any GBP object >>

test@localhost:~/devstack$ gbp policy-action-list

test@localhost:~/devstack$ gbp policy-classifier-list

test@localhost:~/devstack$ gbp policy-rule-list

test@localhost:~/devstack$ gbp policy-rule-set-list

test@localhost:~/devstack$
test@localhost:~/devstack$ gbp policy-target-group-list

test@localhost:~/devstack$
test@localhost:~/devstack$ gbp policy-target-list

test@localhost:~/devstack$
test@localhost:~/devstack$ gbp l3policy-list

test@localhost:~/devstack$
test@localhost:~/devstack$ gbp l2policy-list

test@localhost:~/devstack$

<< Referring to existence of stale Neutron objects >>

test@localhost:~/devstack$ neutron net-list
+--------------------------------------+--------------+----------------------------------------------------+
| id | name | subnets |
+--------------------------------------+--------------+----------------------------------------------------+
| b6f7788c-be15-4544-b26f-5163515be11d | l2p_client-2 | fa2caa03-f20d-42f0-a327-1282c3254ea4 10.0.0.192/26 |
+--------------------------------------+--------------+----------------------------------------------------+
test@localhost:~/devstack$ neutron subnet-list
+--------------------------------------+-------+---------------+----------------------------------------------+
| id | name | cidr | allocation_pools |
+--------------------------------------+-------+---------------+----------------------------------------------+
| fa2caa03-f20d-42f0-a327-1282c3254ea4 | ptg_J | 10.0.0.192/26 | {"start": "10.0.0.194", "end": "10.0.0.254"} |
+--------------------------------------+-------+---------------+----------------------------------------------+
test@localhost:~/devstack$
test@localhost:~/devstack$ neutron port-list
+--------------------------------------+------+-------------------+-----------------------------------------------------------------------------------+
| id | name | mac_address | fixed_ips |
+--------------------------------------+------+-------------------+-----------------------------------------------------------------------------------+
| 146c84f1-3de9-46fc-b421-2a18d1762cd3 | | fa:16:3e:1b:ed:83 | {"subnet_id": "fa2caa03-f20d-42f0-a327-1282c3254ea4", "ip_address": "10.0.0.194"} |
| 5ea5d35c-2652-4c7a-a1f2-9baaeb81062c | | fa:16:3e:39:fa:32 | {"subnet_id": "fa2caa03-f20d-42f0-a327-1282c3254ea4", "ip_address": "10.0.0.193"} |
+--------------------------------------+------+-------------------+-----------------------------------------------------------------------------------+
test@localhost:~/devstack$