digitalWrite() doesn't override analogWrite()

**Describe the bug**
Once PWM is started on a pin with `analogWrite()`, the pin can't be set with `digitalWrite()` anymore.

**Set up**
NRF52840

**To Reproduce**
Steps to reproduce the behavior:
```
analogWrite(LED_GREEN,128);
digitalWrite(LED_GREEN,LOW);
```

**Expected behavior**
PWM on `LED_GREEN` goes to 50%, then pin goes low.
**Actual behavior**
-> pin stays at 50%