Failed to delete router/network

In our automated procedure, after snapshots, sometimes DB start acting in wrong way:

Here we have router with single vm port:
logical-router/faa26a9b-5766-411a-9953-3829e096936b

{u'logical-router': {u'display_name': u'ostf-platform-service-router-185156705',
                     u'fq_name': [u'default-domain',
                                  u'admin',
                                  u'ostf-platform-service-router-185156705'],
                     u'href': u'https://keystone.public.fuel.local:8182/logical-router/4a31d041-86ef-48f3-8d30-4349ec4af86f',
                     u'id_perms': {u'created': u'2017-06-23T06:23:38.605004',
                                   u'creator': None,
                                   u'description': None,
                                   u'enable': True,
                                   u'last_modified': u'2017-06-23T06:24:11.878725',
                                   u'permissions': {u'group': u'admin',
                                                    u'group_access': 7,
                                                    u'other_access': 7,
                                                    u'owner': u'm07031',
                                                    u'owner_access': 7},
                                   u'user_visible': True,
                                   u'uuid': {u'uuid_lslong': 10173705543005960303L,
                                             u'uuid_mslong': 5346283212520769779}},
                     u'name': u'ostf-platform-service-router-185156705',
                     u'parent_href': u'https://keystone.public.fuel.local:8182/project/c0fc2cf7-778e-4cdd-b89f-1fbee635ff4b',
                     u'parent_type': u'project',
                     u'parent_uuid': u'c0fc2cf7-778e-4cdd-b89f-1fbee635ff4b',
                     u'perms2': {u'global_access': 0,
                                 u'owner': u'4ee70bd4aff74e959d9bfe0198450bcb',
                                 u'owner_access': 7,
                                 u'share': []},
                     u'route_target_refs': [{u'attr': None,
                                             u'href': u'https://keystone.public.fuel.local:8182/route-target/1b7f9a67-bc6d-4090-b500-ebe66c9d76f0',
                                             u'to': [u'target:64512:8000007'],
                                             u'uuid': u'1b7f9a67-bc6d-4090-b500-ebe66c9d76f0'}],
                     u'uuid': u'4a31d041-86ef-48f3-8d30-4349ec4af86f',
                     u'virtual_machine_interface_refs': [{u'attr': None,
                                                          u'href': u'https://keystone.public.fuel.local:8182/virtual-machine-interface/60e813f7-0c59-487e-81b7-202393673711',
                                                          u'to': [u'default-domain',
                                                                  u'admin',
                                                                  u'60e813f7-0c59-487e-81b7-202393673711'],
                                                          u'uuid': u'60e813f7-0c59-487e-81b7-202393673711'}]}}

But port does not exist already since it was remote (before?) snapshot:
virtual-machine-interface/60e813f7-0c59-487e-81b7-202393673711
Unknown id: 60e813f7-0c59-487e-81b7-202393673711