Maintenance task to update the existing ovn-lb-hm-ports to the new device_owner has been created and backported due to the main issue was related to neutron-db-sync-tool.

Neutron changes and ovn-provider code base are correct but an error on the backporting of the maintenance task path has been detected on 17.1 last puddle.

Basically the maintenance tasks is doing some calls according to openstacksdk client syntax and 17.1 branches for the ovn-provider code is still using neutronclient.

How reproducible:
See logs of octavia-driver-agent to see the error periodically when the maintenance task is executed.

Actual results:
Existing OVN LB HM ports will not be updated to the new device_owner value due to the failing maintenance task execution.

Expected results:
Existing OVN LB HM ports will be updated to the new device_owner.