Conexión RAK7244 al servidor TTN mediante cable ethernet

Issue: RAK7244 connection via ethernet to router and TTN server
Setup:RAK7244-ethernet-router-ISP-TTN

Server: TTN (EUROPA; eu1)

Details:
Hello everyone, this is my first time on the forum and I appreciate the help in advance.
My problem is that I can’t connect my RAK7244 to TTN server via cable to my home router. I have followed the detailed explanations in the manufacturer’s information sheet and yes, I can make the connection to the router and I get an AP connection, but in the TTN server it does not appear as connected; However, when I connect the RAK7244 via WiFi to my home router as a client, it does appear as connected on the TTN server.
How do I have to configure the connection (RAK, home router and my PC) via ethernet cable to the router, so that it appears on the TTN server as connected?
Thanks, again.
PS. my TTN server is EUROPA(eu1)