unable to access websites from behind pfsense router vm behind another pfsense router vm - No route to host

Network setup (all VM under 1 host): Windows server as a DC under 1 pfSense router, 2 Ubuntu 16.04 under same pfSense. Second pfSense under the first one, with 2 Ubuntu 16.04 under it.

WindowsServer DomainController provides ActiveDirectory services, DNS, DHCP. all Ubuntus are authenticated under AD.

Both pfSense firewalls allow ALL since the network will NOT be connected to the outside world, and it works for current needs.

I can ping www.google.com from 2nd layer Ubuntu, but I cannot access it through a web browser, and receive "No route to host" message under IPv4 connection.

I CAN access website sitting under Windows computer (so second pfSense allows tcp at port 80), and i can access www.google.com from 1st layer Ubuntu.

I cannot think of another way to troubleshoot this problem, any help is appreciated.