Fail to allocate OpenGL texture array in Qt6

Question

Given the following code:

// Helper to print relevant QOpenGLTexture state
QString textureToString(const QOpenGLTexture &textureArray){
    QString out=R"END(
              size: %1x%2
             depth: %3
             faces: %4
            layers: %5
isStorageAllocated: %6
)END";
    return out.arg(textureArray.width()).arg(textureArray.height()).arg(textureArray.depth()).arg(textureArray.faces()).arg(textureArray.layers()).arg(textureArray.isStorageAllocated());
}


// ... 
QOpenGLTexture textureArray(QOpenGLTexture::Target2DArray);

functions = context->extraFunctions();
Q_ASSERT(nullptr != functions);
functions->glDisable(GL_DEPTH_TEST);
functions->glDisable(GL_CULL_FACE);
// Check for specific OpenGL capabilities
if (functions->hasOpenGLFeature(QOpenGLFunctions::OpenGLFeature::Multitexture)){
    qDebug() << "Multitexture is supported.";
}

if (functions->hasOpenGLFeature(QOpenGLFunctions::OpenGLFeature::Framebuffers)){
    qDebug() << "Framebuffer objects are supported.";
}

// Check for specific OpenGL extensions
if (context->hasExtension(QByteArrayLiteral("GL_ARB_vertex_buffer_object")))
    qDebug() << "OpenGL extension GL_ARB_vertex_buffer_object is supported.";
// Print OpenGL version information
qDebug().nospace() << "OpenGL actual version: " << context->format().version().first << "." << context->format().version().second;
qDebug() << "OpenGL vendor:" << QString(reinterpret_cast<const char*>(functions->glGetString(GL_VENDOR)));
qDebug() << "OpenGL renderer:" << QString(reinterpret_cast<const char*>(functions->glGetString(GL_RENDERER)));

const QSize sz(256, 256);
const int num{10};
qDebug() << "num"<<num<<"sz"<<sz;
qDebug().noquote() <<"BEFORE"<<textureToString(textureArray);
textureArray.setSize(sz.width(), sz.height(), num);
qDebug().noquote() <<"AFTER"<<textureToString(textureArray);
textureArray.setMinificationFilter(QOpenGLTexture::Nearest);
textureArray.setMagnificationFilter(QOpenGLTexture::Nearest);
textureArray.setWrapMode(QOpenGLTexture::ClampToEdge);
textureArray.setMipLevels(1);
auto fmt = inferOpenGLFormat(testImage);
QOpenGLTexture::PixelFormat pixelFormat{fmt.first};
QOpenGLTexture::PixelType pixelType{fmt.second};
textureArray.setFormat(QOpenGLTexture::RGBA8_UNorm);
textureArray.allocateStorage(pixelFormat, pixelType);
QOpenGLPixelTransferOptions uploadOptions;
uploadOptions.setAlignment(1);
for(int i=0;i<num;++i){
    //textureArray.setData(testImage);
    qDebug()<<"Uploading "<<i<<"of"<<num;
    textureArray.setData(0, i, pixelFormat, pixelType, testImage.bits(), &uploadOptions);

I get the following output:

Multitexture is supported.
Framebuffer objects are supported.
OpenGL extension GL_ARB_vertex_buffer_object is supported.
OpenGL actual version: 4.6
OpenGL vendor: "NVIDIA Corporation"
OpenGL renderer: "Quadro P400/PCIe/SSE2"

num 10 sz QSize(256, 256)
BEFORE 
              size: 1x1
             depth: 1
             faces: 1
            layers: 1
isStorageAllocated: 0

AFTER 
              size: 256x256
             depth: 1
             faces: 1
            layers: 1
isStorageAllocated: 0

Infering format pixelFormat= QOpenGLTexture::RGBA , pixelType QOpenGLTexture::UInt8 from QImage::Format_RGBA8888
Uploading  0 of 10
Uploading  1 of 10
OpenGL Message: "GL_INVALID_VALUE error generated. Size and/or offset out of range."
Uploading  2 of 10
OpenGL Message: "GL_INVALID_VALUE error generated. Size and/or offset out of range."
Uploading  3 of 10
OpenGL Message: "GL_INVALID_VALUE error generated. Size and/or offset out of range."
Uploading  4 of 10
OpenGL Message: "GL_INVALID_VALUE error generated. Size and/or offset out of range."
Uploading  5 of 10
OpenGL Message: "GL_INVALID_VALUE error generated. Size and/or offset out of range."
Uploading  6 of 10
OpenGL Message: "GL_INVALID_VALUE error generated. Size and/or offset out of range."
Uploading  7 of 10
OpenGL Message: "GL_INVALID_VALUE error generated. Size and/or offset out of range."
Uploading  8 of 10
OpenGL Message: "GL_INVALID_VALUE error generated. Size and/or offset out of range."
Uploading  9 of 10
OpenGL Message: "GL_INVALID_VALUE error generated. Size and/or offset out of range."

As you can clearly see I am unable to allocate a texture array with 10 "layers". It seems that a single element is allocated and it ca be used later when uploading texture data with QOpenGLTexture::setData().

There are no errors indicating that my code fails at the actual QOpenGLTexture::setSize() call but printing the stats after shows the number of layers has not changed, and also trying to use layers beyond index 0 fails.

What am I doing wrong here?