Dhcrelay is not working as expected

I am helping my friend move her DHCP server off of OpenWRT and onto a Windows Server system. LAN works fine as that is simply disable DHCP on OpenWRT and DHCP on Windows Server takes over. The problem is that she has VLANs for some people because of them getting viruses years ago. I am looking at setting up a DHCP relay so that she can have the VLANs also use the Windows Server DHCP. I have run the command "dhcrelay -i eth0.5 -a" and it does not work. If I run "dhcrelay -a" it works but does it on all the interfaces including the wan interfaces. I would like to just do it on specific interfaces but can't find why it is not working. Any ideas?