Help: Networking issues

Hello everybody,

I have some issues at home that I am unable solve, and I hope in your advice.

I start with the description of the networking plan.

My place (2 floors) has Ethernet cables in each room. Cables all go in the basement where I have two gigabit switches to link them together.

In the living room I have the TV cable plug which also provides internet connection through a simple (no wireless) modem.

I have plugged to such modem my RT-AC87U router which then uses one switch port...

Help: Networking issues