You may have to run that a few times in short succession, or from two consoles on the same machine at the same time: That broadcast-dhcp-discover script is a bit unreliable, as it just returns the very first DHCP answer it receives.
And if I read the code from that GitHub link correctly, then that fix addresses multiple interfaces, but still processes only the first answer received via each interface.
On Raspberry Pi OS/Debian systems, sudo dhcpcd -T will yield similar results without having to install nmap - unfortunately in the same arbitrary first answer accepted fashion. 