No pwm output on micro:bit pin 8

[mattybigback]

• Arduino board: BBC Micro:bit v1

• Arduino IDE version (found in Arduino -> About Arduino menu): 2.2.1 (Also using VS Code with the Arduino extension

• List the steps to reproduce the problem below (if possible attach a sketch or
  copy the sketch code in too):

#include <Adafruit_NeoPixel.h>

const int numPixels = 24;
const int pixelPin = 8;

Adafruit_NeoPixel ring = Adafruit_NeoPixel(numPixels, pixelPin);
uint32_t foreground = ring.Color(0x00, 0x00, 0xFF); // r, g, b - blue
uint32_t background = ring.Color(0x10, 0x10, 0x10); // dim white

void setup() {
  pinMode(pixelPin, OUTPUT);
  ring.begin(); // start the NeoPixel display
}

void loop() {
  // blue dot circles around a white background (for PixelRing 24)
  for (int i = 0; i < numPixels; i++) {
    ring.setPixelColor(i, foreground); // set pixel i to foreground
    ring.show();                       // actually display it
    delay(50);                         // milliseconds 
    ring.setPixelColor(i, background); // set pixel to background before moving on
    ring.show(); 
  }
}

Using pin 8 as the LED pin does not work. There's no output at all on the pin. Changing to pin 2 results in a working sketch. Pin 8 is definitely capable of pwm (tested with the below sketch).

const int LED = 8;

void setup() {   
  pinMode(LED, OUTPUT);   
}

void loop(){
  analogWrite(LED, 128);
  delay(1000);
  analogWrite(LED, 1);
  delay(1000);
}