Audio player doesn't work on android. reader not created

Android
1

Hi everyone!
I made an app that allows the user to record an impulse response and then make the offline convolution with a default sound I give him.
I tried this app on mac os and it works fine. Then I moved to android and I ran into some issues.
In fact the player doesn’t work, or rather I’m sure the app find the audio file but then it can’t create the reader (it results null), differently to Mac OS.
I’ve copied the PlayingSoundFilesTutorial, so I can’t figure out what the problem is.
This is my code:

void MainComponent::startPlaying()
{

#if (JUCE_ANDROID || JUCE_IOS)
    const auto exampleFile = File("absolutepath/example.wav");
#else
    --
#endif

if (exampleFile.exists()) {
    auto* reader = formatManager.createReaderFor (exampleFile);
    if (reader != nullptr)
    {
        std::unique_ptr<juce::AudioFormatReaderSource> newSource (new juce::AudioFormatReaderSource (reader, true));
        transportSource.setSource (newSource.get(), 0, nullptr, reader->sampleRate);
        readerSource.reset (newSource.release());
    }
}

}
And another issue is that the recorder records glitchy noise under the real input, while -as I just said- on mac works correctly.

Thank you for your help,
Federico