Comment 2 for bug 1842988

The issue can also be recreated by detaching and reattaching the FIP:
~~~
(overcloud) [stack@undercloud-0 ~]$ openstack server remove floating ip rhel-test3 172.31.0.210
(overcloud) [stack@undercloud-0 ~]$ openstack server add floating ip rhel-test3 172.31.0.210
(overcloud) [stack@undercloud-0 ~]$
~~~

~~~
[root@overcloud-controller-0 ~]# ovn-nbctl find NAT type=dnat_and_snat
_uuid : 61b357c0-1c06-4c22-b0e5-50ef64813cc8
external_ids : {"neutron:fip_external_mac"="fa:16:3e:ee:4b:3b", "neutron:fip_id"="b0c03864-8c79-43b3-9240-370cfbcde904", "neutron:fip_port_id"="b7e9fb53-db4e-4b3e-a6e4-2acbbc4ba9ba", "neutron:revision_number"="2", "neutron:router_name"="neutron-e75c5fb4-29ee-450d-840f-a911c9896256"}
external_ip : "172.31.0.201"
external_mac : "fa:16:3e:ee:4b:3b"
logical_ip : "192.168.0.101"
logical_port : "b7e9fb53-db4e-4b3e-a6e4-2acbbc4ba9ba"
type : dnat_and_snat

_uuid : b0782824-00e9-4b66-bc4b-9d54cf8ec737
external_ids : {"neutron:fip_external_mac"="fa:16:3e:8b:04:4f", "neutron:fip_id"="4fc2b87a-a188-4468-ad40-8b03ed26b56d", "neutron:fip_port_id"="581de757-7b2e-4995-aa84-3c4bc58edd4d", "neutron:revision_number"="2", "neutron:router_name"="neutron-e75c5fb4-29ee-450d-840f-a911c9896256"}
external_ip : "172.31.0.217"
external_mac : "fa:16:3e:8b:04:4f"
logical_ip : "192.168.0.103"
logical_port : "581de757-7b2e-4995-aa84-3c4bc58edd4d"
type : dnat_and_snat

_uuid : 2b58f203-5560-480d-869f-66ddb0d97ed8
external_ids : {"neutron:fip_external_mac"="fa:16:3e:9e:96:da", "neutron:fip_id"="cdeb3dc7-fdc8-493b-9536-edb2163c3d1c", "neutron:fip_port_id"="79f8f865-30c7-48ab-9017-76ce6c007c1b", "neutron:revision_number"="22", "neutron:router_name"="neutron-e75c5fb4-29ee-450d-840f-a911c9896256"}
external_ip : "172.31.0.210"
external_mac : []
logical_ip : "192.168.1.101"
logical_port : "79f8f865-30c7-48ab-9017-76ce6c007c1b"
type : dnat_and_snat
[root@overcloud-controller-0 ~]# ovn-nbctl lr-nat-list neutron-e75c5fb4-29ee-450d-840f-a911c9896256
TYPE EXTERNAL_IP LOGICAL_IP EXTERNAL_MAC LOGICAL_PORT
dnat_and_snat 172.31.0.201 192.168.0.101 fa:16:3e:ee:4b:3b b7e9fb53-db4e-4b3e-a6e4-2acbbc4ba9ba
dnat_and_snat 172.31.0.210 192.168.1.101
dnat_and_snat 172.31.0.217 192.168.0.103 fa:16:3e:8b:04:4f 581de757-7b2e-4995-aa84-3c4bc58edd4d
snat 172.31.0.212 192.168.10.0/24
snat 172.31.0.212 192.168.0.0/24
snat 172.31.0.212 192.168.1.0/24
~~~