Hello,

I have a problem with packet loss on my desktop computer and need to fix it. 
System is configured like this:

Xfinity 1Gig internet

Cable modem = Arris SB8200 (brand new)

10' Cat 6 cable to Deco X20 main unit

2 Deco X20 slave units at other points in the house connected to main unit via wireless. 
 

Wifi works great!!
 

However, the packet loss of the main X20 while gaming is horrendous!!
 

I have a desktop gaming computer connected via Cat 6 cable to the 2nd Ethernet port on the main X20 unit. I am getting very high packet loss when gaming. Very frustrating, so bad that it's not worth gaming. 
 

I have isolated the problem to the X20 by connecting the computer Ethernet to the modem and there is no packet loss.

I tried installing a TP-Link network switch after the modem and plugged both the X20 and the computer into the switch. Computer works great, again no packet loss. But the X20 does not connect.

So I am asking for help in configuring the X20 to not cause packet loss, or configuring it to connect to the internet through the network switch and modem.