TP-Link MR3220 - I don't have cable internet through the wan

I installed and in my opinion correctly configured openwrt on the specified router.
I don't have internet access through the wan.
By default my wan port is on eth1, but I transferred it to eth.02 / so I read in the documentation /.
To me:
port 0 - processor
ports 1, 2, 3, 4 - Lan
wan port does not show me the Luci at all, so I set port 5 in the configuration.
And on eth1 and on eth0.2 and with port 5 and without port 5 ... I don't have internet.
Do you have any idea why this is happening?

The WAN port on the back is directly linked to the CPU as eth1, it isn't part of the switch. The four LAN ports are switched.

In that case what is the reason?
I also tried with eth1 ... it doesn't work.