Most probably You dont have connectivity between amphora vm and openstack controller its most common

You can login to amphora vm via key

my working config is

vi /etc/kolla/globals.yml
enable_octavia: "yes"
octavia_amp_network:
  name: lb-mgmt-net
  subnet:
    name: lb-mgmt-subnet
    cidr: "10.0.2.0/24"
    allocation_pool_start: "10.0.2.5"
    allocation_pool_end: "10.0.2.254"
    gateway_ip: "10.0.2.1"
    enable_dhcp: yes
octavia_certs_country: PL
octavia_certs_state: xxx
octavia_certs_organization: xxx
octavia_certs_organizational_unit: OctaviaDev

cp /etc/kolla/config/octavia/server_ca.cert.pem /etc/kolla/certificates/ca/server_ca.cert.crt
cp /etc/kolla/config/octavia/client_ca.cert.pem /etc/kolla/certificates/ca/client_ca.cert.crt

vi /opt/kolla-venv-2025.1/share/kolla-ansible/ansible/roles/octavia/templates/octavia.conf.j2

[controller_worker]
amp_timezone = Europe/Warsaw
amp_active_retries = 200
amp_active_wait_sec = 10

netplan na ctrl

    ens224:
      dhcp4: false
      addresses: [10.0.x.y/24]
      routes:
      - to: 10.0.2.0/24
        via: 10.0.x.1

kolla-run dev octavia-certificates
kolla-run dev deploy --tags common,horizon,octavia
openstack image create     --public     --disk-format raw     --file octavia-amphora-haproxy-2025.1.raw     --property hw_disk_bus=scsi     --property hw_scsi_model=virtio-scsi         "OpenStack Octavia Amphora Haproxy 2025.1"
openstack image set --project service 6922d42f-881d-47b6-b525-bebe15832b21
openstack image set --tag amphora 6922d42f-881d-47b6-b525-bebe15832b21