I have just run an installation of WO with https://github.com/VirtuBox/wo-nginx-setup on a VM Vultr - Ubuntu 18.04, and during the NGINX build step the SSH connection has been broken.
I then decided to access the Vultr SHELL that transmits the screen, giving access to the native shell of vm. At this point I came across the Server Reboot Log.
With Server restarted, I tried to access through SSH again and the error I get is: Permission denied (publickey).