the tutorial explains that the host key will change after a rebuild, and that the change will produce an error each time you reconnect to that ip, but doesn't say how to fix it. the tutorial should mention that the old entry in known_hosts can be easily removed with ssh-keygen, eg
ssh-keygen -R 192.168.99.99
and then have the user connect again to witness the absence of the error.
the tutorial explains that the host key will change after a rebuild, and that the change will produce an error each time you reconnect to that ip, but doesn't say how to fix it. the tutorial should mention that the old entry in known_hosts can be easily removed with ssh-keygen, eg
ssh-keygen -R 192.168.99.99and then have the user connect again to witness the absence of the error.
https://tutorials.rc.nectar.org.au/changing-instances/04-rebuilding