ADDITIONAL SYSTEM INFORMATION :
OS: Windows 10 x64.
Java version: JDK 10.0.2, also reproducible with 11.0.3, 12.0.1.

A DESCRIPTION OF THE PROBLEM :
With the dual monitor setup, when the heavyweight popup window is requested to show on a non-primary display, it is showed on a primary display instead, at seemingly random location.

This behavior is only reproducible with JDK 10 and higher.

REGRESSION : Last worked in version 8u212

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Run the attached example
2. Drag the main frame from the primary display to a non-primary one.
3. Click "Create Popup" button.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The popup appears at the correct location right under the main frame.
ACTUAL -
The popup is showed on the other (primary) display.

---------- BEGIN SOURCE ----------
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class HeavyWeightPopupSample {

    static class ShowPopupActionListener implements ActionListener {

        private final Component component;

        ShowPopupActionListener(Component component) {
            this.component = component;
        }

        @Override
        public void actionPerformed(ActionEvent actionEvent) {
            JButton button = new JButton("Hello world");
            PopupFactory factory = PopupFactory.getSharedInstance();

            // Set the popup coordinates such that the popup window is not "parented" by the
            // component and becomes a heavyweight window.
            final int popupX = component.getX() + 351;
            final int popupY = component.getY() + 251;
            Popup popup = factory.getPopup(component, button, popupX, popupY);
            popup.show();
        }
    }

    public static void main(final String[] args) {
        JFrame frame = new JFrame("HeavyWeightPopup Sample");
        ActionListener actionListener = new ShowPopupActionListener(frame);
        JButton start = new JButton("Create Popup");
        start.addActionListener(actionListener);
        frame.add(start);
        frame.setSize(350, 250);
        frame.setVisible(true);
    }
}
---------- END SOURCE ----------

FREQUENCY : always