diff_against for ios_config for not working with --diff mode

[dvenur...@gmail.com]

I am trying to use diff_against to show the before and after changes with --diiff but it is not working

can some was worked already on it can you please help here.

Ansible version:-2.9.10

playbook:-

---

- hosts: ciscorouter

gather_facts: no

tasks:

- name: Pre-check

ios_config:

lines:

- username xxxx privilege 15 password 0 xxxx

save_when: changed

#check_mode: yes

diff_against: "running"

register: change

Thanks in advance.