Ipv4 nointernet ipv6 ok on EdgeRouter Light

I am new to OpenWrt and try to get an Ubiquiti EdgeRouter Light up and running.
My config is Internet-Experiabox-OpenWrt-laptop so I have double nat. Experiabox is the router from
my provider which provides internet, tv and telephone.
I also have a pfSense router connected to the same Experiabox and there ipv4 works correct.
In this box I have defined that the pfSense is the DMZ for ipv4.
I think that when I connected the EdgeRouter for the first time ipv4 network did work, but I'm not sure.
If I test ping in the OpenWrt (Network Diagnostics) it works ok.
Status gives IPv4 Route:
wan 0 main
lan 0 main
lan 0 main
The only thing I changed from the default setup is the password.
What am I missing?