Problem with the current in a multiphase buck converter

I am a student of electrical and computer engineering and am currently working on a project that involves the study of a multiphase buck converter or synchronous buck converter (2 phases, in my case).

The following table shows the parameters of the converter I'm building.

Therefore, in my project I'm using a closed-loop PI controller to control the output voltage. With the following Arduino code I obtain the desired output voltage but the current only flows through only one phase, instead of half in each 2 phases.

// Parâmetros globaisdouble Kp = 0.00825;                             // Ganho proporcionaldouble Ki = 50;                                  // Ganho integraldouble t = 0.01;                                 // T = 1/fsw = 1/20000 = 5*10^-5 s = 0.05 ms ; t = T/5 = 0.05/5 = 0.01 ms --> 5 amostrasunsigned long last_time;double proportional = 0.0;double integrator = 0.0;                         // Variável para armazenar o termo integral anteriordouble error_sum = 0.0;                          // Soma acumulada dos errosdouble last_error;double V;double Vo;double Vref = 5.0;double R1 = 30000.0;                             // Resistência do módulo do sensor de tensãodouble R2 = 7500.0;                              // Resistência do módulo do sensor de tensão// Limites do duty cycle PWMconst int dutyCycleMin = 20;                     // Duty cycle é máximo quando OCR1A é 20 = 399*0.05const int dutyCycleMax = 379;                    // Duty cycle é máximo quando OCR1A é 379 = 399*0.95void setup() {  pinMode(9, OUTPUT);                            // Set the PWM pin as output  pinMode(10, OUTPUT);                           // Set the PWM pin as output  TCCR1A = _BV(COM1A1) | _BV(COM1A0) | _BV(COM1B1) | _BV(WGM11);  // Set non-inverted mode for COM1A, inverted mode for COM1B  TCCR1B = _BV(WGM13) | _BV(CS10);                                // Set Fast PWM mode with prescaler of 1  ICR1 = 399;                                                     // Set the TOP value for the PWM frequency (16MHz / (1 * 20000) - 1 = 399)}// Função para ler o valor da tensão à saída do conversordouble lerTensao() {  double tensao = analogRead(A0);                // leitura do pino analógico A0  V = tensao * (Vref / 1024);                    // Conversão da leitura da tensão  Vo = (V / (R2/(R1 + R2)));                     // Multiplicar por 5 devido ao divisor de tensão do sensor  return Vo;}// Função controlador PIvoid PI_control() {  unsigned long current_time = millis();  int delta_time = current_time - last_time;  if(delta_time >= t) {    double setpoint = 6.0;                           double feedback = lerTensao();                   double error = setpoint - feedback;    // Cálculo do termo proporcional    proportional = Kp * error;    // Cálculo do termo integral    error_sum += error;    integrator = (Ki*t) * error_sum;    // Cálculo do duty cycle do PWM    int dutyCycle = round(proportional + integrator);    // Restrição do duty cycle dentro dos limites permitidos    if (dutyCycle > dutyCycleMax) {     dutyCycle = dutyCycleMax;    } else if (dutyCycle < dutyCycleMin) {      dutyCycle = dutyCycleMin;    }  last_error = error;  last_time = current_time;  OCR1A = dutyCycle;  OCR1B = dutyCycle;  }}void loop() {  PI_control();}

To obtain the parameters of the PI controller (Kp and Ki) I used an article where the same parameters are calculated but for a converter with one phase. I don't know if these values change for a two-phase converter.I don't know what I'm doing wrong so that the current only flows through one phase. If anyone can help me resolve this situation, I'd appreciate it.

José Alves