BlurMaskFilter blur radius question on canvas with scale transformation

Question

I have two views: View1 and View2. View1 draws a point with BlurMaskFilter on a canvas with a scale amount 3F. View2 first draws that point on a bitmap at 1x scale, and then the bitmap is drawn on the canvas, with 3x scale.

Now I expect the two views to draw the visually identical images, but it doesn't. Anyone can tell why it's like this?

View1:

class DemoView1 : View {
    constructor(context: Context?) : this(context, null)
    constructor(context: Context?, attrs: AttributeSet?) : super(context, attrs)

    private var paint: Paint = Paint()

    init {
        paint.apply {
            strokeWidth = 500F
            style = Paint.Style.FILL
            color = Color.RED
            strokeJoin = Paint.Join.ROUND
            strokeCap = Paint.Cap.ROUND
            maskFilter = BlurMaskFilter(200F, BlurMaskFilter.Blur.NORMAL)
        }
    }

    override fun onDraw(canvas: Canvas) {
        canvas.scale(3F, 3F)
        canvas.drawPoint(0F, 0F, paint)
    }
}

View2:

class DemoView2 : View {
    constructor(context: Context?) : this(context, null)
    constructor(context: Context?, attrs: AttributeSet?) : super(context, attrs)

    private var paint: Paint = Paint()

    init {
        paint.apply {
            strokeWidth = 500F
            style = Paint.Style.FILL
            color = Color.RED
            strokeJoin = Paint.Join.ROUND
            strokeCap = Paint.Cap.ROUND
            maskFilter = BlurMaskFilter(200F, BlurMaskFilter.Blur.NORMAL)
        }
    }

    @SuppressLint("DrawAllocation")
    override fun onDraw(canvas: Canvas) {
        val bitmap = Bitmap.createBitmap(measuredWidth, measuredHeight, Bitmap.Config.ARGB_8888)
        val bitmapCanvas = Canvas(bitmap)
        bitmapCanvas.apply {
            drawPoint(0F, 0F, paint)
        }
        canvas.scale(3F, 3F)
        canvas.drawBitmap(bitmap, 0F, 0F, Paint())
    }
}

Demo result:

The upper one is View1, and lower one is View2.