Hi, 

I bought the TL-WN823N for an old laptop as the WiFi is not good. However, this adapter is either very slow or slower still. I've spent hours searching online for solutions and fiddling with settings. 80% of the time the speed test result is less than 35Mbps, upload speed is almost always faster!

Here are the details requested.

Modem / Router:  Technicolor TG789vac v2

Windows 10 Home, 10.0.19042 Build 19042

Connection Settings

Protocol: Wi-Fi 4 (802.11n)

Security type: WPA2-Personal

Network band: 2.4GHz

Network channel: 11

Link speed: 144/144 (Mbps)

Manufacturer: Realtek Semiconductor Corp.

Description: TP-Link Wireless USB Adapter

Driver Version: 1030.38.712.2019

I get 320Mbps from the same network on my phone and Tower.