known_hosts module reports changed when nothing has changed

Why does my task report say that it has changed when nothing has changed?
- hosts: localhost
become: false
gather_facts: false
tasks:
- name: Remove non existing host key from known_hosts file
known_hosts:
name: 192.168.122.230
key: 192.168.122.230 ssh-rsa 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
state: absent
register: reg_known_hosts

- name: Show known_host register
debug:
var: reg_known_hosts


```
TASK [Remove non existing host key from known_hosts file] *****
changed: [localhost]

TASK [Show known_hosts register] ****
ok: [localhost] => {
"reg_known_hosts": {
"changed": true,
"diff": {
"after": "192.168.122.230 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIzlnSq5ESxLgW0avvPk3j7zLV59hcAPkxrMNdnZMKP2\n",
"after_header": "/home/sxkx/.ssh/known_hosts",
"before": "192.168.122.230 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIzlnSq5ESxLgW0avvPk3j7zLV59hcAPkxrMNdnZMKP2\n",
"before_header": "/home/sxkx/.ssh/known_hosts"
},
"failed": false,
"gid": 1000,
"group": "sxkx",
"hash_host": false,
"key": "192.168.122.230 ssh-rsa ssh-rsa AAAAB3NzaC1yc2EAA

It seems that the issue you've filed, Ansible Issue #78598 was noticed. It was possible to reproduce, got a small fix and an easyfix label.

Since further verification and testing is outstanding, you might be able to add the three proposed lines of code into your own known_host.py and test it. You could provide after testing an update on the Ansible Issue.

StackExchange DevOps Q#16448, answer score: 1