When the host can't access ntp servers at boot (installed while offline, or network requests filtered), the boot process stalls for 10 minutes. It's only after the 10 minutes timeout that xsconsole is displayed to the console. This is caused by the chrony-wait service.
This is somewhat frightening for users who don't know what's happening. The systemd units ordering should probably be reviewed to allow xsconsole and xapi to start, maybe with a warning displayed in xsconsole stating that no ntp server could be contacted.