Confirmed: you did shutdown the instance using the Google Console and then restarted it. From that time on, you can access the instance, right?
IP address updated.
I never touched any settings, like the FIrewall rules. It shows tcp:22 is open. It seems like my server is down.
So shouldn't using the option "Lauch SSH Console" always work?
Link in message "We are unable to connect to the VM on port 22. Learn more about possible causes of this issue.":
At that link I see: The instance is shut down. Verify that the instance is up and running. See this guide for information on how you can troubleshoot an unhealthy instance.
Now looking at: