The shadow(Elevation) looks unnature and only be show in the bottom

[bingningO]

Hello, I'm using setElevation() and setArrowElevation() to add a shadow for the balloon, but it looks unnature, you can see from the screenshot.
Hope it can be looks like a real shadow, refer the MaterialDesign.

Or maybe I misunderstood how to set it ?

here is my code of the Balloon view,

@Composable
fun PopupToolTipWithText(
    text: String,
    display: Boolean,
    alignType: PopupToolTipAlignType,
    onDismiss: () -> Unit,
    anchorComposable: @Composable () -> Unit,
) {
    val lifeCycleOwner = LocalLifecycleOwner.current
    val backgroundColor = MaterialTheme.colorScheme.secondary

    val builder = rememberBalloonBuilder {
        // !!! here is how I set elevation
        setElevation(16)
        setArrowElevation(16)

        setArrowOrientationRules(ALIGN_ANCHOR)
        setArrowPositionRules(ArrowPositionRules.ALIGN_ANCHOR)
        setWidth(BalloonSizeSpec.WRAP)
        setHeight(BalloonSizeSpec.WRAP)
        setPadding(8)
        setMarginHorizontal(16)
        setCornerRadius(4f)
        setBackgroundColor(backgroundColor)
        setBalloonAnimation(OVERSHOOT)
        setOnBalloonDismissListener {
            onDismiss()
        }

        // need to setPreferenceName with ShowCounts to avoid balloon not showing
        setPreferenceName("TooltipBalloon")
        setShowCounts(Int.MAX_VALUE)

        // to avoid memory leak if leaving this page with balloon not dismissed
        setLifecycleOwner(lifeCycleOwner)
    }

    Balloon(
        builder = builder,
        balloonContent = {
            Text(
                text = text,
                color = MaterialTheme.colorScheme.onPrimary,
                style = MaterialTheme.typography.bodySmall
            )
        }
    ) { balloonWindow ->
        if (display) {
            when (alignType) {
                PopupToolTipAlignType.TOP -> balloonWindow.showAlignTop()
                PopupToolTipAlignType.BOTTOM -> balloonWindow.showAlignBottom()
            }
        }
        anchorComposable()
    }
}

and the sample View to call the Balloon composable,

@Composable
fun TestBalloon() {
    Box(modifier = Modifier.fillMaxWidth().height(200.dp).background(Color.White), contentAlignment = Alignment.Center) {

        var display by remember { mutableStateOf(false) }
        PopupToolTipWithText(
            text = "Balloon text text",
            display = display,
            alignType = TOP,
            onDismiss = {
                display = false
            },
        ) {
            Button(onClick = { display = true}) {
                Text(text = "display balloon")
            }
        }
    }
}