Next I had to fix/undo a "network hardening" customization specifically in the Divested build configuration by commenting the interface=br-lan line in /etc/dnsmasq.conf (aka add a # before the line of code). Then I rebooted my network (MUST reboot to take effect).
edit: I first put this post as solution but I'm not done with the vlan part. So I will probably use this thread for help as I go.. 