Hi @Qwis,

Please refer to the following steps to troubleshoot potential speed issues and improve the speed of your Range Extender.
    1. First of all, we recommend using http://www.speedtest.net to test the speed accurately. Speedtest APP/CLI tools (https://www.speedtest.net/apps/) would be better.
    2. Before testing speed, make the extender's 2.4ghz and 5ghz SSID different from the router's to ensure your Laptop/Phone is connected to the extender's 5GHz Wi-Fi. 
    3. If the signal light on the extender is red, move it closer to the host Router to receive a better wireless signal. 
    4. Adjust the location and antennas on the extender for optimal performance. Check this link for detailed guidance: How to place your wireless Range Extender for optimal reception and performance
    5. Connect to the Wi-Fi network of the host Router, and run a speedtest for comparison.
    6. If the wireless speed is expected, but the Ethernet speed is less than 100m/s, please refer to the “Specifications” of your extender to check whether it has a 1 x 10/100Mbps Ethernet Port.
Note: Range Extenders extend WiFi coverage rather than boosting speed. Affected by wireless interferences, extender size, and antenna direction, devices connected via an extender typically experience ‌about 50% slower speeds‌ than a direct router as data travels through two wireless hops: Device ⇄ Extender ⇄ Router. 
If you think the speed is still not expected, please send here the result of the above troubleshooting steps.