Testing the speed via WIFI may have some limitation.
Please test the speed via a WIRED connection (LAN cable). Connect your personal device to the router using the LAN cable and you should be seeing much higher speeds.
Here's what you need to take note of:
1. Connect to the 2.5Gbps LAN port on the router. It's labelled on the device.
2. Your personal device (your hand phone/laptop/etc) need to support 2Gbps. Connect to the 2.5Gbps LAN port on your device.If you don't have one, you can purchase a USB-C to 2.5Gbps ethernet adapter separately.
3. Ensure your LAN cable is Cat5e or above