When I launch/close the modal bottom sheet it causes my lazy Column list to reload, why?

I think var showBottomSheet by remember { mutableStateOf(false) } is causing a problem.
In this code showBottomSheet = true this causes refresh only once when I click on the row.
If I set it to showBottomSheet = !showBottomSheet, then every time I click it recomposes the lazy column.

What else can I do to avoid this recomposition?

fun TrainListContent() {
val viewModel = CCViewModel()
val sheetState = rememberStandardBottomSheetState()
var showBottomSheet by remember { mutableStateOf(false) }
var clickedTrainNumber by remember { mutableStateOf("") }
val trainList = viewModel.filteredTrains.collectAsLazyPagingItems()

LazyColumn(modifier = Modifier.background(Color.LightGray))
{
    if (trainList.loadState.refresh is LoadState.Loading ||
        trainList.loadState.refresh is LoadState.Error
    ) {
        item {
            HandleLoadState(
                loadState = trainList.loadState.refresh,
                onRetry = { trainList.retry() }
            )
        }
    }
    items(
        count = trainList.itemCount,
    ) { index ->
        val train = trainList[index]
        if (train != null) {
            TrainListRow(
                train = train,
                onClick = {
                    clickedTrainNumber = it
                    showBottomSheet = true
                }
            )
        }
        Spacer(
            modifier = Modifier
                .height(5.dp)
        )
    }
    if (trainList.loadState.append == LoadState.Loading) {
        item {
            CircularProgressIndicator(
                modifier = Modifier
                    .fillMaxWidth()
                    .wrapContentWidth(Alignment.CenterHorizontally)
            )
        }
    }
}
if (showBottomSheet) {
    ModalBottomSheet(
        onDismissRequest = { showBottomSheet = false },
        sheetState = sheetState,
        modifier = Modifier.height(700.dp)
    ) {
        viewModel.setTrainNumber(clickedTrainNumber)
        val trainSchStat = viewModel.trainSchPaged.collectAsLazyPagingItems()
        Sample(trainList = trainSchStat)
    }
}

}