Why calling digitaWrite(pinNum,HIGH) before setup() not working?

Question

I am writing a library to operate a linear actuator, let's call the library ActuatorV2. It is composed of two files, a .h and and .cpp files. To create an object, I instantiate the object as follows

Actuator act(pulsePin,directionPin,enablePin);

Within the constructor of the object, four tasks are performed:

1) pin assignment,

2) setting pin modes,

3) setting pulse frequency

4) enabling the actuator.

When performing the fourth task (enabling), I simply set the enablePin to HIGH as follows digitalWrite(enablePin,HIGH); There is absolutely nothing special here, but for some odd reason, when setup() is called in the sketch, the enablePin is set back to LOW. I know this because I have an LED light connected to the enablePin, and I visually monitor it during the operation.

Any idea why this happens?

I am aware that in the documentation of setup() here, it is clearly stated that pinMode() should be placed in setup(). But I have used the approach shown in the MWE before a few months ago, and it was working just fine.

---

Hardware used

MacBook Pro

Arduino Due

MWE

Sketch

#include <ActuatorV2.h>

// defining actuator pins and properties
const int pulstPin      = 4;
const int directionPin  = 5;
const int enablePin     = 6;
const int pulseFrequency= 500;

// initializing the actuator
Actuator act(pulstPin, directionPin, enablePin, pulseFrequency);

void setup() {
    // do nothing
}

void loop() {
    // do nothing
}

Library (Actuator.h, Actuator.cpp)

Actuator.h

#ifndef Actuator_h
#define Actuator_h

#include<Arduino.h>

class Actuator{
    private:
    // private variables
    // pins
    int _pulsePin;
    int _directionPin;
    int _enablePin;
    // pulse frequency parameters
    int _pulseFrequency;
    int _pulseDelay = 5;   // 2.5 microseconds manufacturer recommendation
    int _interpulseDelay;

    // private methods
    void assignPins(int pulsePin, int directionPin, int enablePin);
    void setPinModes();

    public:
    // constructors
    Actuator(int pulsePin, int directionPin, int enablePin, int pulseFrequency);
    // public methods
    void setPulseFrequencyParameters(int freq);
    void enable();
};

#endif

Actuator.cpp

# include<ActuatorV2.h>
# include<Arduino.h>

Actuator::Actuator(int pulsePin, int directionPin, int enablePin, int pulseFrequency){
    // 1) pin assignment
    assignPins(pulsePin,directionPin,enablePin);

    // 2) setting pin modes
    setPinModes();

    // 3) setting pulse frequency
    setPulseFrequencyParameters(pulseFrequency);

    // 4) enable actuator
    enable();
}

void Actuator::assignPins(int pulsePin, int directionPin, int enablePin){
    _pulsePin = pulsePin;
    _directionPin = directionPin;
    _enablePin = enablePin;
}

void Actuator::setPinModes(){
    pinMode(_pulsePin,OUTPUT);
    pinMode(_directionPin,OUTPUT);
    pinMode(_enablePin,OUTPUT);
}

void Actuator::setPulseFrequencyParameters(int pulseFrequency){
  int _pulseFrequency = pulseFrequency;
  int minPeriod = 10; // 10 micro-seconds which is 4 X 2.5 (manufacurer recommended pulse width for reliable operation)
  /*
  ---------------------------------------------------------------------
  Pulse shape

  3.3 V 
        |  |``````````|                     |``````````|
        |  |          |                     |          |
        |__|          |_____________________|          |__________ time
  0   V
           \__________/\____________________/
                pd              ipd
           \________________________________/
                     one pulse 

  pd: pulse delay. Minimum 3 micro seconds
  ipd: inter-pulse delay. Minimum 3 micro seconds
  ---------------------------------------------------------------------
  */

  float period = 1.0/((float) pulseFrequency);

  if (period < minPeriod){
    _pulseDelay = 5;
    _interpulseDelay = 5;
  } else  {
    _pulseDelay = 5;
    _interpulseDelay = period - _pulseDelay;
  }
}

void Actuator::enable(){
  digitalWrite(_enablePin,HIGH);
  delay(500); // delay to observe the result if effective.
}