SSH warning: “POSSIBLE DNS SPOOFING DETECTED!”

I got an warning from SSH when i logged onto my vps.

myvps@Desktop:~$  ssh-copy-id -i .ssh/id_rsa.pub  myvps@Laptop
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: ".ssh/id_rsa.pub"
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed

/usr/bin/ssh-copy-id: ERROR: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
ERROR: @       WARNING: POSSIBLE DNS SPOOFING DETECTED!          @
ERROR: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
ERROR: The ECDSA host key for laptop has changed,
ERROR: and the key for the corresponding IP address 192.168.0.103
ERROR: is unknown. This could either mean that
ERROR: DNS SPOOFING is happening or the IP address for the host
ERROR: and its host key have changed at the same time.
ERROR: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
ERROR: @    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
ERROR: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
ERROR: IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
ERROR: Someone could be eavesdropping on you right now (man-in-the-middle attack)!
ERROR: It is also possible that a host key has just been changed.
ERROR: The fingerprint for the ECDSA key sent by the remote host is
ERROR: SHA256:1n48LRTTlQUqoNlSZmT99m/suucIGj1VsD7NF6hw5RQ.
ERROR: Please contact your system administrator.
ERROR: Add correct host key in /home/myvps/.ssh/known_hosts to get rid of this message.
ERROR: Offending ECDSA key in /home/myvps/.ssh/known_hosts:3
ERROR:   remove with:
ERROR:   ssh-keygen -f "/home/myvps/.ssh/known_hosts" -R "app1"
ERROR: ECDSA host key for laptop has changed and you have requested strict checking.
ERROR: Host key verification failed.

The solution comes from the above error log:

This is often because a serverhas reinstalled the system,

After reinstallation, the LAN IP in the cluster is redistributed, and the /etc/hosts of each node is not completely modified and synchronized.

ssh-keygen -f "/home/myvps/.ssh/known_hosts" -R "app1"

Then :

ssh-copy-id -i .ssh/id_rsa.pub  myvps@Laptop

Problem solved. Hope this can help you!