Comment 18 for bug 1918410

I've tested isc-dhcp 4.4.1-2.1ubuntu5.20.04.3 from focal-proposed. Works as expected.

root@ff-dhcp:~# apt list isc-dhcp-client
Listing... Done
isc-dhcp-client/focal-proposed,now 4.4.1-2.1ubuntu5.20.04.3 amd64 [installed,automatic]

I can see no 'dhclient' entries in dmesg after the initial "apparmor_parser -r /etc/apparmor.d/sbin.dhclient" reload (neither after 'netplan apply', nor after reboot):

$ dmesg | grep dhclient
[...]
[327577.704123] audit: type=1400 audit(1655988372.103:4665): apparmor="STATUS" operation="profile_replace" label="lxd-ff-dhcp_</var/snap/lxd/common/lxd>//&:lxd-ff-dhcp_<var-snap-lxd-common-lxd>:unconfined" name="/{,usr/}sbin/dhclient" pid=1595322 comm="apparmor_parser"

dynamic IP address is assigned via NetworkManager:
$ ip addr show eth0
[...]
178: eth0@if179: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 00:16:3e:0a:83:de brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.238.94.241/24 brd 10.238.94.255 scope global dynamic noprefixroute eth0
       valid_lft 3509sec preferred_lft 3509sec

$ nmcli -o
eth0: connected to netplan-eth0
        "eth0"
        ethernet (veth), 00:16:3E:0A:83:DE, sw, mtu 1500
        ip4 default, ip6 default
        inet4 10.238.94.241/24
[...]