Unfortunately, an issue that seems to come and go is the mouse freezing when it isn’t used for over 5 seconds. This is long enough that it appears to be an intermittent issues with the mouse but is actually completely repeatable (just hold the mouse still and count to ten!).
After working through the various options, I narrowed this down to Power Saving on the actual Intel Bluetooth device. To fix this:
Go to Device Manager (simple press the Windows key on your keyboard and type Device Manager, then press enter)
Expand the Bluetooth section and locate the Intel(R) Wireless Bluetooth(R) device
Right click on it and select Properties
Uncheck the box that says Allow this computer to turn off this device to save power
Click Ok and you can now close device manager,
Problem should be solved!