Clear Your Android Device’s Bluetooth Cache
Removing your Android device’s cache files may help fix disconnection issues. This is harmless both to your device and to your Square Reader. Removing cache files is not possible on iOS devices. Please follow these steps:
Go to the Settings on your Android device.
Select Application Manager
Click the 3 dots in the top right corner and select All System Apps.
Scroll and tap on the Bluetooth app.
Stop your device’s Bluetooth app by tapping Force Stop.
Next tap Clear Cache.
Restart your device and try repairing it to your Reader again. Visit this support centre article for a refresher on how to connect your Square Reader via Bluetooth.
If the steps are a bit different on your particular Android device, you may want to search how to clear the Bluetooth cache for your specific Android Device.