setValidationVisible not working

Hi guys,

I am using TextFields with setRequired(true) and setValidationVisible(true) inside a Window. The validation is well catched durring the validate() call but the setValidationVisible(true) doesn't seem to work. There is no red outline on my TextField and the "v-textfield-error" is not added to the component class.

I am using it exactly the same way in a other view but without window and it is working properly.

Note : I am using the delarative syntax.

Here is my code :

feedWindowRoot.textFieldName.setRequired(true);
feedWindowRoot.textFieldName.setValidationVisible(true);

feedWindowRoot.buttonSave.addClickListener(new Button.ClickListener() {
@Override
public void buttonClick(Button.ClickEvent event) {
try {
    feedWindowRoot.textFieldName.validate();
}
catch (Validator.InvalidValueException e) {
    feedWindowRoot.textFieldName.setValidationVisible(true);
    Notification.show("This field is required");
}
});

Any idea ?

Thank you