If connected with Bluetooth, after wake up from sleep or hibernation, you usually need to click the mouse or trackpad, or press a key on the keyboard to reconnect your device. Some users reported that it doesn't work, but so fare we can't reproduce this in order to fix it. In case your devices do not reconnect:
Toggle Bluetooth
- In Windows Settings, turn off Bluetooth
- Wait 5 seconds
- Turn Bluetooth on again.
- Now click or press your device.
Or restart your computer.
This is, of course, difficult if your input devices do not work! You can connect both Magic Keyboards and the Magic Trackpad 2 with the provided USB cable with your computer.USB connections should always work.