Vodafone/Astoria Easybox 904 xDSL

Hello! Long time ago i bought Easybox 904 xDSL from something like a thrift store for like 3 euros. It seemed like a cool router so i bought it but then i didn't know that i can't use it "directly" because i live in Bulgaria and we don't have DSL and that kind of stuff, only regular RJ45 cable from the ISP. It was in a bootloop and i flashed the original firmware which solved the bootloop but i couldn't manage to make it work with internet. I've installed OpenWRT long time ago and i couln't make it work so i lost hope and put it in the drawer. Yesterday i found it and I wanted to try to resque it again. When I hook it up to my main router through lan port (so that it acts like a second router) there is internet on the output lan port of the router but none on the wifi. I want to use it as a main router (With rj45 WAN input and WIFI output). Any ideas how can i do that? Thanks in advance

Tried https://forum.openwrt.org/search?context=topic&context_id=131609&q=Easybox%20904&skip_context=true ?

Be aware that the eb904xdsl runs out of steam around 55-60 MBit/s WAN speed and that its WLAN is fragile at best. It has very cool unique features, but functionally -especially with OpenWrt in mind-, it's 'difficult'...

I highly recommend SMP image (default WAN for ETH):