audioCallBack returning inputChannelData samples with 0 values

MacOSX and iOS
1

I have the following quite simple audioCallBack code to receive 8 channels of audio from a MOTU 828es, mix to 2 channels and send them over a socket connection to a node.js server:

void audioCallBack::audioDeviceIOCallbackWithContext (const float* const* inputChannelData,
                                              int numInputChannels,
                                              float* const* outputChannelData,
                                              int numOutputChannels,
                                              int numSamples,
                                              const juce::AudioIODeviceCallbackContext& context)
{   
    for (int channel = 0; channel < numInputChannels; ++channel) {
        if (inputChannelData[channel] == nullptr) {
            DBG("inputChannelData[" << channel << "] is null");
        }
    }

    // Ensure that there are exactly 2 output channels
    jassert(numOutputChannels == 2);

    // Process the incoming audio data
    for (int sampleNo = 0; sampleNo < numSamples; ++sampleNo) {
        float leftTotal = 0.0f;
        float rightTotal = 0.0f;

        for (int channel = 0; channel < numInputChannels; ++channel) {
            const float* inputData = inputChannelData[channel];
            if (inputData[sampleNo] != 0.0f)
                DBG(inputData[sampleNo]);
            leftTotal += inputData[sampleNo] * speakerConfig.speakers[channel]->leftGain;
            rightTotal += inputData[sampleNo] * speakerConfig.speakers[channel]->rightGain;
        }
        // send samples to TCPConnection
        if (tcpConnection != nullptr) {
            tcpConnection->sendSamples(leftTotal, rightTotal);
        }
    }
}

From the output, I see that I do have inputChannelData (no nullPtr), but that the samples are always 0. This is confirmed on the node.js server side, where I am accumulating sample buffers, but with all sample values at 0. The code is working on a Windows machine, but not on my MacBook Pro. I am working under OSX 14.5 and am using the version 8.00 of JUCE. I put a similar request on the general discussion, but after no resolution there thought it might be more appropriate in the Apple discussion.

2

Just to add - while I am receiving 0 sample values, I can see the channels being received in Reaper with appropriate values, if I open it.

3

This looks more like a network communication issue, than an audio related one.

Can you improve the situation by using SocketOptions with tcpConnection, and by increasing the buffer sizes?