OVRManager.display returning null

Hello, I think the problem is that it is not going through all the frequencies that it collects in "freq" try this.

private float[] _freqs;
private float _freqsSelect;

    private void Start()
    {
        _freqs = OVRManager.display.displayFrequenciesAvailable;
        _freqsSelect = _freqs[0];

        CheckFrequencyDevice(_freqs);
    }

// In this function it loops through all the frequencies returned by OVRManager.display.displayFrequenciesAvailable
private void CheckFrequencyDevice(float[] f)
    {
        for (int i = 0; i < f.Length; i++)
        {
            if (f[i] > _freqsSelect)
            {
                _controllerProgressBar.LoadTMPProgressBar(2.0F);
                _freqsSelect = f[i];
            }
        }
       //Here you can choose the frequency you want. In my case, if it has returned one of more than 90, it means that there is a frequency of 120 and I send it to another function for its assignment. (You can make it more elegant than the example case)
        if(_freqsSelect > 90.0F)
        {
            ToAssingFrequencyDevice(120.0F);
        }
        else
        {
            ToAssingFrequencyDevice(70.0F);
        }
    }

    private void ToAssingFrequencyDevice(float hz)
    {
        OVRPlugin.systemDisplayFrequency = hz;
    }

Greetings and I hope it works for you.