Template inputs does not show validation messages for bootstrap 4. I get the same issue using Kartik password input

I am unable to get validation messages to display at the bottom of an input like kartik password. I get the same issue if I took Yii activeform passwordInput and customize it with a button at the end using a template. How can I fix my code so that validation messages shows for all inputs.

<?php $form = ActiveForm::begin(['id' => 'form-signup', 'enableAjaxValidation' => true]); ?>
                        <div class="form-group mb-3">
                        	 <?= $form->field($model, 'username')->textInput(['autofocus' => true,
                        	     'placeholder' => \Yii::t('app','Enter your username')]) ?>
                        </div>

                        <div class="form-group mb-3">
                             <?= $form->field($model, 'email')->input('email',
                                 ['placeholder' =>  \Yii::t('app','Enter your email')]) ?>
                        </div>

  					 <div class="form-group mb-3">
                             <?= $form->field($model, 'password')->widget(PasswordInput::classname(), 
                                 [ 'options' => ["class" => "form-control is-invalid", 'placeholder' =>  \Yii::t('app','Enter your password')]]); ?>
                         </div> 

                        <div class="form-group">
                        	<?= $form->field($model, 'accept_term')->checkbox()
                        	->label(Yii::t('app',"I accept").'<a href="javascript: void(0);" class="text-dark"> '.Yii::t('app', 'Terms and Conditions').'</a>');?>
                        </div>

                        <div class="form-group mb-0 text-center">
                            <?= Html::submitButton(Yii::t('app','Sign Up'), ['class' => 'btn btn-primary btn-block', 'name' => 'signup-button']) ?>
                        </div>

                    <?php ActiveForm::end(); ?>