Try uninstalling the driver from device manager and the reinstall the driver; you can download the Bluetooth driver at the following link:
Once the driver is reinstall, after connecting the mouse to the computer via Bluetooth, make sure the setting "Allow the computer to turn off this device to save power" in unchecked.
- In the Search Charms, type Device Manager.
- Browse Bluetooth.
- Right click on the mouse driver shown and click on Properties.
- In the power management window, uncheck the option "Allow the computer to turn off this device to save power".
If the problem persists, please access the BIOS, when restart the system press F2 on your keyboard to enter the bios and then set your BIOS to default setting by pressing F9 on your keyboard and then press F10 to save all changes and then check and see if the problem is resolved.
If the problem persists, try with a BIOS update, you can download the latest version here:
Please see F7 BIOS Update Instructions for Intel® NUC
I hope this can help.