An unique SSID on the slow router? Also is the slow router a different make and model?
In my house, I have 3 routers (I have a pretty big house) connected Lan-to-Lan and the wifi speed on one of the routers is pretty slow.
On the first floor, I have the main router (TP-Link) connected to my ISP's modem, DHCP ON, ip 192.168.0.1. Also on the first floor, I have another router (D-Link), connected to the first router through the Lan port, DHCP OFF, ip 192.168.0.2 and on the second floor I have a third router(D-Link) connected to the first router through the Lan port, DHCP OFF, ip 192.168.0.3. All routers are using the same WiFi SSID, same password and DIFFERENT channels. Router 1 and 2 (1st floor) can give me full speed both on wired and wireless connections (60mb/s), 3rd router (2nd floor), gives me full speed on wired connection but on wireless connection it only gives me 1~4 mb/s which is pretty awful. All routers are using the latest firmware.
Do you guys have any idea of what the problem might be?
Thank you!

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