How can I create in MAUI Android a thumbnail from a byte array?

Question

MAUI. I have read (from a database) a byte array named "receiptDocumentBytes".

I want to create a thumbnail of this image, and only pass that thumbnail among my various objects in the application (the images themselves would be quite large).

So once I have my receiptDocumentBytes byteArray I have tried to do this:

if (receiptDocumentBytes != null)
    {
        Microsoft.Maui.Graphics.IImage image;
        using (MemoryStream ms = new MemoryStream(receiptDocumentBytes))
#if ANDROID
            image = Microsoft.Maui.Graphics.Platform.PlatformImage.FromStream(ms);
#else
            image = Microsoft.Maui.Graphics.Win2D.W2DImage.FromStream(stream);
#endif

        //Create the thumbnail of this image:
        using (Stream stream = new MemoryStream(receiptDocumentBytes))
            {
                if (image != null)
                    {
                        int thumbnailSize = Preferences.Get("ThumbnailSize", 600);
                        //The largest dimension will be set to 'thumbnailSize' pixels while maintaining the aspect ratio:
                        IImage thumbnailImage = image.Downsize(thumbnailSize, true);
                        using (MemoryStream memStream = new())
                            {
                                thumbnailImage.Save(memStream);
                            }
                    }
            }
    }

How does this behave ? Oddly.

My MemoryStream ms (the first using) is populated (it has a length, a capacity, etc), but the image object

image = Microsoft.Maui.Graphics.Platform.PlatformImage.FromStream(ms);

is not - it shows Height and Width = System.NullReferenceException: Object reference not set to an instance of an object, all the other properties being null.

However, the object itself is not null, thus passing the test

if (image != null)

Then, on the line

IImage thumbnailImage = image.Downsize(thumbnailSize, true);

the execution does not show any exception, but jumps to the end of my

using (Stream stream = new MemoryStream(receiptDocumentBytes))

So the code does not execute, is not caught by my error handling, and it does not create any thumbnail image.

So.... what am I doing wrong here, please ?

Thank you.