Microbit reading magneto values and writing to LED

I am able to create a BLE connection to my microbit following the basic connections tutorial.
I can read temperature and accelerometer data, and can read the LEDMatrixState.
I cannot write to the LED - there are no error message, just the microbit display does not change.
When I try reading magnetometer values (data, bearing) I receive a service error saying that the characteristics are not published by the connected device.

My microbit has the factory default code.

Any help would be much appreciated.