Rundeck ansible F5 errors

I feel you have used incorrect parameter as pool member host: "{{ansible_default_ipv4.address}}", it will be member. Find the correct details and modify accourdingly. 

- name: "Disable from pool {{ pool_name }}"
  bigip_pool_member:
    provider:
      server: "{{ f5_ipaddress }}"
      user: "{{ f5_user }}"
      password: "{{ f5_pwd }}"
      validate_certs: "no"
      transport: "rest"
    state: forced_offline
    pool: "{{ pool_name }}"
    partition: "Common"
    member: "{{ pool_member_ip }}"
    port: "{{ pool_member_port }}"
  delegate_to: localhost
  when: action == "disable"
  tags: f5_manage

Still issue let me know.. 

FYI

The parameter host in the bigip_pool_member module should specify the IP address or hostname of the pool member you want to disable, but you have used {{ansible_default_ipv4.address}}. This variable typically represents the IP address of the Ansible control machine, not the pool member's IP address.

To fix this, you should replace host: "{{ansible_default_ipv4.address}}" with member: "{{ pool_member_ip }}", assuming you have a variable pool_member_ip that holds the IP address of the pool member you want to disable.