Hello,

I am having a strange problem with my Archer C6U router when used with other TP-LINK devices. My setup is following (also please see pic below):

I have an Archer C5 with Wi-Fi enabled provided by my ISP. This router is connected to the Internet and I don't have any admin access to it.
From the Archer C5 I have:
 
1. An ethernet connection to an Archer C6U (which is running in Access Point mode with Wi-Fi disabled). To this Archer C6U I have 3 other devices connected via ethernet cables (a desktop PC, a Playstation and an Apple TV).

2. An ethernet connection to TL-PA4010 which then transmits the Internet connection to a TL-WPA4220 (Wi-Fi disabled). From TL-WPA4220 I have a wired connection to a laptop.

Now for the issue:
When I was running this setup (with the Archer C6U connected) the laptop connected to TL-WPA4220 was having serious network stability issues. There were a lot of timeouts and lost packets and it was basically impossible to connect to Internet on this laptop.

I tried to search for a solution and I found that Archer C6U had DHCP server enabled (even though it was set up in Access Point mode). I disabled the DHCP server and the connection issues seemed to disappear. There were no drops, timeouts or any other issues on the laptop connected to TL-WPA4220 for some time. Unfortunately, the problem reappeared after several days.

When I replaced the Archer C6U with a spare Asus RT-N19 (also running in Access Point mode with Wi-Fi disabled) the problem disappeared altogether.

Can someone figure out why is the Archer C6U interfering with the TP-WPA4220 this much and how can this be prevented?