Please check the followings:
1. Check the cable connection environment
Connect the OTG cable included with the device, and connect the USB cable to the Foot Switch.
*They won't operate if connected the other way.
2. Make sure nothing is wrong with the USB cable
*If you have an extra USB cable, try switching with it and see if it operates.
3. Make sure there is enough battery
*The device may not operate properly if there is not enough battery.
If it is low on battery, please charge and see if it operates.
4. Make sure pairing is complete
Device and Foot Switch needs to be paired if they are connected via Bluetooth.
Please check if you see Foot Switch model number in the [Settings]->[Bluetooth] section.
Please contact GVIDO Support Center if your issue does not apply to the above or if you see no improvements after confirming the above.