ADDITIONAL SYSTEM INFORMATION :
Observed on Windows 10

Failing configuration:
Java: Temurin JDK 11.0.12+7
JavaFX: javafx-sdk-11.0.2

Successful configuration:
Java/JavaFX: liberica JDK 8u302-full

A DESCRIPTION OF THE PROBLEM :
In Java 11 with JavaFX SDK 11, a call to ListView.getSelectedItem() will return the previously selected item if called from the invalidation listener on ListView.getSelectionModel().getSelectedItems().

It works just fine on Liberica's Java 8 build that includes JavaFX bundled inside.

REGRESSION : Last worked in version 8u301

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the included code and watch as the list items get selected once per second. Note that the label will not match the selected item.


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Label should always match the selected item in the list.
ACTUAL -
Label will match the selected item in the list if the user selects an item in a list. However if the list item is selected programmatically (which will happen once per second in this example code) the label will show the value of the previously selected item.

---------- BEGIN SOURCE ----------
import javafx.application.Application;
import javafx.application.Platform;
import javafx.beans.binding.Bindings;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.ListView;
import javafx.scene.layout.FlowPane;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;



public class ListViewBugDemo extends Application{

    @Override
    public void start(Stage primaryStage) throws Exception {
        
        Pane root = new FlowPane();
        
        ListView<String> list = new ListView<>();
        list.getItems().addAll("One", "Two", "Three");
        
        Label selectedItemLabel = new Label();
        
        //This way works just fine
// selectedItemLabel.textProperty().bind(list.getSelectionModel().selectedItemProperty());
        
        
        //This way also works just fine
// selectedItemLabel.textProperty().bind(
// Bindings.createStringBinding(
// () -> list.getSelectionModel().getSelectedItems().isEmpty() ? null : list.getSelectionModel().getSelectedItems().get(0),
// list.getSelectionModel().getSelectedItems())
// );
        
        //This way results in a binding that always has the previously selected item
        selectedItemLabel.textProperty().bind(
                Bindings.createStringBinding(
                        () -> list.getSelectionModel().getSelectedItem(),
                        list.getSelectionModel().getSelectedItems())
                );
        
        
        root.getChildren().addAll(list, selectedItemLabel);
        
        primaryStage.setScene(new Scene(root, 400, 400));
        primaryStage.show();
        
        new Thread(() -> {
            while(true) {
                try {
                    Thread.sleep(1000);
                    Platform.runLater(() -> list.getSelectionModel().select((list.getSelectionModel().getSelectedIndex() + 1) % list.getItems().size()));
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                }
            }
        }).start();
        
    }
    
    public static void main(String[] args) {
        launch(args);
    }
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Replace the binding with either of the commented out bindings above it.

FREQUENCY : always