Speaker Diarization Inference - unable to detect number of speakers when oracle_num_speakers set to False
I am new to nemo and following this Colab notebook - https://github.com/NVIDIA/NeMo/blob/main/tutorials/speaker_tasks/Speaker_Diarization_Inference.ipynb

When I try set num_speakers = None in manifest file and set config.diarizer.clustering.parameters.oracle_num_speakers=False , and run it without oracle vad diarization,  it only detects one speaker even for the example file provided in the notebook


This is the code I amended:

```
an4_audio_url = "https://nemo-public.s3.us-east-2.amazonaws.com/an4_diarize_test.wav"
an4_audio = wget.download(an4_audio_url, data_dir)

`import json
meta = {
    'audio_filepath': an4_audio, 
    'offset': 0, 
    'duration':None, 
    'label': 'infer', 
    'text': '-', 
    **'num_speakers': None,** 
    'rttm_filepath': None, 
    'uem_filepath' : None
}
with open('data/input_manifest.json','w') as fp:
    json.dump(meta,fp)
    fp.write('\n')



**config.diarizer.clustering.parameters.oracle_num_speakers=False**

```

Can someone help me with why it is not able to predict two speakers?