Bootcamp Windows 10: Bluetooth works, but mouse not found
Solution 1:
Turns out this was not an issue with the Bootcamp installation or its drivers. I did not know you had to hold the power botton of the mouse to make it pair. So in order to get it to work, go to Bluetooth, turn Bluetooth on, turn mouse on, hold power button pressed, the mouse will then show up under Bluetooth devices, then pair it.