TP-Link UB400 Quick Start Manual page 12

We see complaints of short-range or cut off often because the adapter is connected to the back of
a desktop computer, where there is a lot of random radio noise generated by the processor and
system parts.
Moving the adapter to the front of the computer often helps, or using a USB 2.0 extension cable
to move the adapter away from the computer.
An Intel white paper also confirmed that poorly shielded USB 3.0 ports will cause radio
interference. If your device is having range issues when plugged into a USB 3.0 port, a USB
extension cable can help with this.
2) Ensure the Bluetooth receiver has a good signal
The Bluetooth range also depends on BOTH the receiving and the transmitting devices. Please
test your receiving Bluetooth device with a mobile phone to confirm its range is acceptable.
3) Eliminate possible interference
Operation range can be affected by physical obstructions (walls, people, etc.), wireless
interference (Wi-Fi routers, Wireless TV adapters, etc.).
4) Stop high traffic applications
If you're watching videos or streaming music from an ONLINE source, please make sure the
audio dropout issue is not caused by slow network speed.
Q6: Why my Bluetooth devices can't find my PC after UB400/UB4A is installed successfully?
Make sure your PC has enabled the Bluetooth function. Please follow the steps below: right click
on the Bluetooth icon on your PC > Open Settings > More Bluetooth Options
Note: Similar process for the other windows OS.