From our end, the host names are getting listed in the server reboot IT Automation Template form.
Please ensure the supported agent versions for listing the hostnames are 18.4.0 & above for Windows and 16.6.0 & above for Linux. Read our documentation to confirm on the agent versions and upgrade the same.
If the issue persists, please mail us the hostname(s) at email@example.com for further analysis.
Looking forward to hearing from you.