I have made a slidable composable whicht sits under the top app bar but unfortunately the composable does not slide under the top app bar but instead over it. Here the code:

Scaffold(
    topBar = {
		Column {
			TopAppBar(
				...
			)
			AnimatedVisibility(
				visible = (connectionState == BluetoothConnectionState.Disconnected),
				enter = slideInVertically(),
				exit = slideOutVertically(targetOffsetY = { value -> -value }),
				content = { ConnectionStatusBannerComponent(onAction = { }) }
			)
		}
	},
)

Does someone have an idea?

Try

Modifier.zIndex()

I would suggest you use a Scaffold for the TopAppBar/contents

@jaqxues of course I do, just left it out in my snippet 🙂