Deploying Ubuntu with Autoinstall stopt working

Problem:
I was able to deploy Ubuntu 24.04 with foreman, but this stopped working. And I do not know what has changed. Now when I boot the target computer it boots by PXE and loads the install iso as expected. But then the setup is asking all the normal questions. All answers in the autoinstall are ignored.

checking “cloud-init schema --system” shows that user-data at /var/lib/cloud/instances/iid-datasource-none/cloud-config.txt is Emty. Nothing to validate

In the foreman web page the “Preseed Autoinstall cloud-init user data” template is rendering fine.

#cloud-config
autoinstall:
  version: 1
  apt:
    geoip: false
    preserve_sources_list: false
    primary:
      - arches: [amd64, i386]
        uri: http://archive.ubuntu.com/ubuntu
      - arches: [default]
        uri: http://ports.ubuntu.com/ubuntu-ports
    disable_components: [multiverse]
    disable_suites: [backports,security,updates] 
  user-data:
    disable_root: false
    fqdn: lc0111892.wago.local
    users:
    - name: root
      gecos: root
      lock-passwd: false
      hashed_passwd: $5$gpfE5PljEkSPFPcC$1v2wmruMWaxVR8EewT.56lLWNcd7OzT2.PJR3W0Nz22
      ssh_authorized_keys: ["ssh-rsa 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 foreman-proxy@svlicm01001.wago.local"]
  keyboard:
    layout: de
    toggle: null
    variant: ''
  locale: de_DE.UTF-8
  ssh:
    allow-pw: true
    install-server: true
  updates: security
  proxy: http://apt-proxy.wago.local:3142
  storage:
    layout:
      name: lvm
      password: DiesesPasswordAndern
  packages:
  - openssh-server
  - sed
  - ca-certificates
  - cups
  - ubuntu-drivers-common
  - unzip
  - wireless-tools
  - wpasupplicant
  - xdg-user-dirs
  - xdg-user-dirs-gtk
  - xkb-data
  - xorg
  - yelp
  - zenity
  - zip
  - openprinting-ppds
  - printer-driver-pnm2ppa
  - pulseaudio
  - apport-gtk
  - file-roller
  - 7zip
  - arj
  - lzip
  - lzop
  - ncompress
  - rpm2cpio
  - rzip
  - sharutils
  - unace
  - unalz
  - unar
  - gnome-calendar
  - gnome-snapshot
  - remmina
  - remmina-common
  - remmina-plugin-rdp
  - remmina-plugin-secret
  - remmina-plugin-vnc
  - rhythmbox-plugins
  - shotwell
  - shotwell-common
  - simple-scan
  - rhythmbox
  - totem-plugins
  - language-pack-de
  - language-pack-gnome-de
  - gnome-user-docs-de
  - hunspell-de-at-frami
  - hunspell-de-ch-frami
  - hunspell-de-de-frami
  - wngerman
  - wogerman
  - wswiss
  - winpr-utils
  kernel:
    flavor: hwe
  late-commands:
  - wget -Y off http://svim01001.wago.local/unattended/finish?token=b946f27b-7d74-4db7-849b-83cac588760b -O /target/tmp/finish.sh
  - curtin in-target -- chmod +x /tmp/finish.sh
  - curtin in-target -- /tmp/finish.sh

Also the Grub 2 template renders fine


#
# This file was deployed via 'Preseed default PXEGrub2 Autoinstall' template
#
# Supported host/hostgroup parameters:
#
# blacklist = module1, module2
#   Blacklisted kernel modules
#
# lang = en_US
#   System locale
#

set default=0
set timeout=10

menuentry 'Preseed default PXEGrub2 Autoinstall' {
  linuxefi boot/ubuntu-server-24-04-boot-disk-oXdcw8hIYdN3-vmlinuz root=/dev/rd/0 rw auto ip=dhcp BOOTIF=c4:c6:e6:78:d4:88 ramdisk_size=1500000 fsck.mode=skip autoinstall url=http://svim01001.wago.local:80/ubuntu-server/24.04-x86_64.iso cloud-config-url=/dev/null "ds=nocloud-net;s=http://svim01001.wago.local/userdata/c4:c6:e6:78:d4:88/" console-setup/ask_detect=false locale=de_DE localechooser/translation/warn-light=true localechooser/translation/warn-severe=true hostname=lc0111892.wago.local domain=wago.local
  initrdefi boot/ubuntu-server-24-04-boot-disk-oXdcw8hIYdN3-initrd
}

Expected outcome:
Answers to the setup questions are loaded from “Preseed Autoinstall cloud-init user data”. Setup is completed without input.

Foreman and Proxy versions:
Version 3.10.0

Foreman and Proxy plugin versions:
foreman-tasks 9.1.1
foreman_ansible 14.0.0
foreman_dhcp_browser 0.0.8
foreman_hooks 0.3.17
foreman_puppet 6.2.0
foreman_remote_execution 13.0.0
foreman_templates 9.4.0
foreman_webhooks 3.2.2
puppetdb_foreman 6.0.2

Distribution and version:
RHEL 9