So, with no responses. I was able to figure out a solution myself.
The answer is, that Windows is the device the comes up with the route and inserts it into the routing table. This involves a little know setting called "class based route addition" which can be turned on/off. Windows assumes you will be working within your network class and address the route accordingly.
The solution is to use powershell.
Add-VpnConnectionRoute -name "VPN Name" -DestinationPrefix 192.168.X.X/23
this is an example, but you can figure it out. once this has been added, it effectively creates a route just for the VPN. This fixes the issue and routing starts working.
in case you are wondering, Mac has an equivalent line of code
sudo networksetup -setadditionalroutes "VPN Name" 192.168.X.X 255.255.254.0 192.168.X.1
best of luck.