FIXED!.. and I told you I was a dumb cunt!
New video coming soon.
dhclient
part of isc-dhcp-client
runs on things that you put in /etc/network/interfaces
config is /etc/dhcp/dhclient.conf
ISP doesn't respond to discover
dhcpcd
runs on pi for things not in /etc/network/interfaces
can run in addition and populate stale values in adapter
doesn't get required ipv6 as standard
not needed because of settings in /etc/network/interfaces
config is /etc/dhcpcd.conf
needs to be disabled
disable dhcpcd
sudo systemctl stop dhcpcd.service
sudo systemctl disable dhcpcd.service
modify /etc/dhcp/dhclient.conf
end dhcp-client-identifier 1:dc:a6:32:c1:8f:ad
adjust timeout
/etc/systemd/system/network-online.target.wants/networking.service