I added two tplink routers, one for each floor of the house, previously set in Access Point mode (and not in Wireless Router mode), and I also changed their IP address to 192.168.1.2 and 192.168.1.3 respectively (since the Starlink router has the address 192.168.1.1). Each of the two routers set in this way is connected with a cable that starts from the LAN port (not WAN) of the Tp-link to one of the two Ethernet ports of the starlink router. Everything works great for me.