Comment 8 for bug 1961088

Looks like bind_ip is set to 127.0.0.1 by default:

https://github.com/openstack/octavia/blob/3c5bbbc189efe9f3ed4caae04a23d7a13718d368/octavia/common/config.py#L286-L288
    cfg.IPOpt('bind_ip', default='127.0.0.1',
              help=_('IP address the controller will listen on for '
                     'heart beats')),

It is used in UDPStatusGetter

https://github.com/openstack/octavia/blob/3c5bbbc189efe9f3ed4caae04a23d7a13718d368/octavia/amphorae/drivers/health/heartbeat_udp.py#L40-L48
class UDPStatusGetter(object):
    """This class defines methods that will gather heartbeats
    The heartbeats are transmitted via UDP and this class will bind to a port
    and absorb them
    """
    def __init__(self):
        self.key = cfg.CONF.health_manager.heartbeat_key
        self.ip = cfg.CONF.health_manager.bind_ip

which is used by the Octavia health manager:

https://github.com/openstack/octavia/blob/3c5bbbc189efe9f3ed4caae04a23d7a13718d368/octavia/cmd/health_manager.py#L42-L45

At the first glance, not having `bind_ip` set to a different value seems relevant, I'll continue looking further.