[Samba] Machine choosing unexpected logonserver in multi-dc domain 4.2.1

[Fred Smith]

I have the following setup in a samba 4.2.1 multi-dc domain

DC1 - 10.10.2.50
DC2 - 10.10.2.60
DC3 - 192.168.103.2

I have a site and subnet setup for each DC in Active Directory Sites
and Services

DC1 server in site DC1 with subnet 10.10.2.50/32
DC2 server in site DC2 with subnet 10.10.2.0/24
DC3 server in site DC3 with subnet 192.168.103.0/24

DC3 has dhcpd setup giving machines on it's network IPs 192.168.103.100+

When I login to a Win7 machine in DC3s site/network, it always gets
logonserver DC1. I have tried leaving/join domain. The only way I can
get it to use DC3 as logonserver is to stop samba on DC1 and DC2.

I use the following command on the Win7 machine to verify the logonserver

echo %logonserver%

When I had this similar configuration in samba 4.1.x machines on DC3s
network would always choose DC3 as the logonserver.