systemd dependency problem means isc-kea-ctrl-agent does not autostart at bootup

I have the following packages installed under Ubuntu 18.04 from deb https://dl.cloudsmith.io/public/isc/kea-1-6/deb/ubuntu bionic main:

ii  isc-kea-common                  1.6.3-isc0044120200730112858        amd64        Common libraries for the ISC Kea DHCP server
ii  isc-kea-ctrl-agent              1.6.3-isc0044120200730112858        amd64        ISC Kea DHCP server REST API service
ii  isc-kea-dhcp4-server            1.6.3-isc0044120200730112858        amd64        ISC Kea IPv4 DHCP server
ii  isc-kea-dhcp6-server            1.6.3-isc0044120200730112858        amd64        ISC Kea IPv6 DHCP server

PROBLEM: isc-kea-ctrl-agent is not automatically started by systemd when the machine reboots (but it does start if you manually run systemctl start isc-kea-ctrl-agent)

CAUSE: /lib/systemd/system/isc-kea-ctrl-agent.service contains:

[Install]
WantedBy=kea-dhcp4-server.service
WantedBy=kea-dhcp6-server.service

This should instead say:

[Install]
WantedBy=isc-kea-dhcp4-server.service
WantedBy=isc-kea-dhcp6-server.service

WORKAROUND:

• systemctl edit isc-kea-ctrl-agent.service
• enter the [Install] section exactly as above, and save.
• systemctl reenable isc-kea-ctrl-agent.service