I have an issue with my old router, that I want to use as an Access Point in my apartment. Old Router got its DHCP disabled, a unique static IP and SSID assigned. I am using LAN-to-LAN ethernet ports.
When I connect it with the ISP modem (router1) directly with a single cable, it all works just fine. I can see both Wifi networks and router2 serves as a useful switch as well.
The problem comes up when I connect those two via in-wall installed CAT6 cable (+RJ45 sockets). This cable connects the main living room (router1) and my home office (desired place for router2). In this scenario, the router2 is dead, I cannot access its admin setup via browser anymore, router1 admin says its offline, router2 Wifi SSID is down (no internet connection).
Nevertheless, in-wall installed CAT6 cable in my home office works just fine when I connect it to a PC, laptop, PS4 etc.
Any hints or tips?