Setting dhcp-server authoritative removes all dhcp configuration

I was having trouble with periodic errors: duplicate ip's assigned in my log, as decribed in forums...

here https://community.ubnt.com/t5/EdgeMAX/uid-lease-duplicate-errors-in-syslog/m-p/1207526#M60419

and here https://community.ubnt.com/t5/EdgeMAX/dhcpd-duplicate-lease/td-p/691071 

So I attempted to make my DHCP servers authoritative. After committing this config, ALL dhcp configutaiton is removed, including the dhcp servers. I tried this twice. 

admin@router:~$ configure
[edit]
admin@route# set service dhcp-server shared-network-name LAN1 authoritative enable
[edit]
admin@router# set service dhcp-server shared-network-name LAN2_IoT authoritative enable
[edit]
admin@router# set service dhcp-server shared-network-name VLAN.1003 authoritative enable
[edit]
admin@router# commit
[ service dhcp-server ]
No DHCP lease subnets configured for shared network name 'LAN2_IoT'.
At least one DHCP lease subnet must be configured for each shared network.
DHCP server configuration commit aborted due to error(s).
[edit]
admin@router# exit
Warning: configuration changes have not been saved.
exit
admin@router:~$

 Is this a bug or is there a reasonable explainaiton?