@siam_928 

The TX/RX Rate is the negotiated rate between the client and the router, which is influenced by factors such as the client's location, signal strength, and wireless interference etc., Could you please provide more details about the specific environment you are referring to?

And what client devices are affected?

  @siam_928 

Hi, are there any walls or other obstacles when you are 15-20 feet away from the router? based on the screenshots, those clients are connected to 2.4G WiFi. How about 5G client devices?

Besides, please provide detailed speedtest results at different locations/distances, including the TX/RX rate displayed on the web interface, link speed on the client device and actual internet speed.

You could refer to this guide to check link speed on the client device: How to check the associated/link speed on a wireless client

For internet speed tests, please use https://www.speedtest.net or the speedtest APP/CLI(https://www.speedtest.net/apps) to test speed accurately.

In addition, please also let us know the model no. of your client device that you used for testing.

  @siam_928 

Hi, the router is in the first room, right? and the two rooms are about 15-20 feet from each other and one wall in between, right?

What is the brand and model no. of the phone you used for the testing? 

Please also confirm if the issue happens only with 2.4G WiFi, or both 2.4G WiFi and 5G WiFi have the same issue. Try changing the WiFi channel and channel width to see if it helps.

  @siam_928 

Can you tell whether you were connected to the C64 router WiFi or the Archer C20 repeater when running the tests?

Since we are unable to reproduce the issue on our end, To locate and resolve the issue, we have to know clearly about your topology and situation, and please also let us know if it is convenient for you to test and debug with our senior engineers, if so, I will escalate your case to our senior engineer via email.