Hit the "Forget" option on the app and try to pair the device one more time following these steps:
1. Confirm that the Remote Keyboard Host App icon is present in your computer system tray.
2. Confirm that both the computer and the mobile device are connected to the same wireless network.
3. Launch the Remote Keyboard Mobile App on your mobile device. The Devices screen, showing devices on your wireless network, will show on the Devices list.
4. Initiate the pairing process by tapping on a device in the device list.
5. If this is the first time pairing, you are required to authenticate via a QR code scan.
For further reference https://downloadmirror.intel.com/24967/eng/Remote-Keyboard-User-Guide02.pdf.