Hi.... I want to use my range extender as a wifi adaptor over ethernet cable.

My Asus tuf gaming laptop has Realtek GbE family controller and i have 2 different brand new CAT6 ethernet cables two meters long and a CAT5 ethernet cable. I configure RE500X at repeater mode.

The problem 1 is 

-When i try both Cat6 cables, Tx/Rx Rates at status screen for RE500X are 10/10 Mbps (seems problematic).

-When i try Cat5 cable, Tx/Rx Rates at status screen for RE500X are 100/100 Mbps as expected.

Internet speed tests correspond to written tx and rx rates above.

The problem 2 is

-There are never 1Gbps/1Gbps Tx/Rx rates at status screen that i really try to get.

Am i doing something wrong? Thx.