MediaPlayer on android device can't find default audio output

The program Examples/Qt-6.7.2/demos/mediaplayer on an Android 14 tablet with a connected bluetooth 5.0 speaker and set as default audio output does not immediately play the sound on the speaker, but first on the built-in speakers and then after several seconds on the Bluetooth speaker. It seems that when starting the program there is no AudioInput devices by default.

1- open a sample mp4 file on the Android device with bluetooth speaker connected : the sound is directly on bluetooth speaker

2- launch demos/mediaplayer on the same device and load the same mp4 video file : the movie is correctly played but the song is thirst played on built in speaker and after a few seconds on bluetooth speaker

in another program by putting this code in the constructor of my class

const QList<QAudioDevice> audioDevices = QMediaDevices::audioOutputs();
 for (const QAudioDevice &device : audioDevices)

{     qDebug() << "AudioDevice output ID: " << device.id() << Qt::endl;     qDebug() << "Description: " << device.description() << Qt::endl;     qDebug() << "Is default: " << (device.isDefault() ? "Yes" : "No") << Qt::endl; }

i see this debug

AudioDevice output ID:  "2" 
Description:  "Built in speaker (SM-T220)" 
Is default:  No 
AudioDevice output ID:  "352" 
Description:  "Bluetooth (Music Care)" 
Is default:  No 
 

In my qml file :

MediaPlayer {
        id: bellSound
        source: "sounds/bell.mp3"
        audioOutput: AudioOutput

{             id: audioOutputBell             volume: 1         }

    }
 when bellSound.play() first the sound is out from the Built-In speacker and after a few second to the Bluetooth speaker

gradle.properties :
androidBuildToolsVersion=34.0.0

androidCompileSdkVersion=android-34

androidNdkVersion=26.1.10909125

buildDir=build

qt5AndroidDir=~/Qt/6.7.2/android_arm64_v8a/./src/android/java

qtAndroidDir=~/Qt/6.7.2/android_arm64_v8a/./src/android/java

qtMinSdkVersion=23

qtTargetAbiList=arm64-v8a

qtTargetSdkVersion=34