The “Scan Timeout” display message may mean that your reader is not close enough to the sensor. Try holding the screen of your reader closer to your FreeStyle Libre 3 Plus sensor.
If the “Scan Timeout” persists after you’ve tried scanning please complete the convenient online sensor support request form, or contact Customer Care Customer Care which is available at 1-855-632-8658 7 days a week from 8AM to 8PM Eastern Time; excluding holidays.