Please go to settings> Bluetooth> locate your stylus > Forget This Device. Then, reboot your iPad and restart GoodNotes.
If it issue persist, follow these steps or contact the manufacture for further support.
- Open the app and find its Settings menu.
- Open the Settings menu to enable the stylus support.
GoodNotes > Options > Settings >Smart Stylus
- You may need to open a notebook to pair your stylus.
- Press the stylus button. The LED starts blinking blue.
- Pairing is completed when the LED stays on.