DHCP address keeps getting generated with netplan and bonded interface
Solution 1:
Networkd never invokes dhclient. This running dhclient process is the result of something else on your system besides your netplan config. Killing the process and checking that it does not return (including after a reboot) is the correct approach.
If it does return, you will want to check for other configuration under /etc, such as /etc/network/interfaces.