Why are input fields not available on the site on the phone?

Question

Layout

Hello! On the site in phones and smartphones in Google Chrome in the "Version for PC" mode, the input and select fields are not available on one of the pages. They do not have a disabled or readonly flag. But they do not open: selects do not open, and nothing can be entered in the input fields on the form. The site is made on Yii2. What could be the reason?

The code:

<?php
        $block_show = $OrderCheckoutHelper->getBlockDisplay('giving_order_point_1_block');
    ?>
    <div class="row giving_order_point_1_block" style="display: <?php echo $OrderCheckoutHelper->getBlockDisplay('giving_order_point_1_block');?>;">
        <div class="col-sm-6">
            <?php echo $form->field($model, 'recipient_info[country_delivery]')
                ->dropDownList($countryOptions, ['prompt' => 'Страна', 'options' => $block_show == 'none' ? [] : $OrderCheckoutHelper->getActualFieldInfo('model', 'recipient_info', 'country_delivery', '[recipient_info][country_delivery]',true)['options']])
                ->label(false); ?>
        </div>
        <div class="col-sm-6">
            <?php echo $form->field($model, 'recipient_info[region_delivery]')
                ->textInput(['placeholder' => 'Регион/область', 'value' => $block_show == 'none' ? null : $OrderCheckoutHelper->getActualFieldInfo('model', 'recipient_info', 'region_delivery', '[recipient_info][region_delivery]')['value']])
                ->label(false); ?>
        </div>
    </div>

    <div class="row giving_order_point_1_block" style="display: <?php echo $OrderCheckoutHelper->getBlockDisplay('giving_order_point_1_block');?>;">
        <div class="col-sm-12">
            <?php echo $form->field($model, 'recipient_info[city_delivery]')
                ->textInput(['placeholder' => 'Город/Населенный пункт', 'value' => $block_show == 'none' ? null : $OrderCheckoutHelper->getActualFieldInfo('model', 'recipient_info', 'city_delivery', '[recipient_info][city_delivery]')['value']])
                ->label(false); ?>
        </div>
    </div>

    <?php
        $block_show = $OrderCheckoutHelper->getBlockDisplay('giving_order_point_2_block');
    ?>
    <div class="row giving_order_point_2_block" style="display: <?php echo $OrderCheckoutHelper->getBlockDisplay('giving_order_point_2_block');?>;">
        <div class="col-sm-12">
            <?php echo $form->field($model, 'recipient_info[street_delivery]')
                ->textInput(['placeholder' => 'Улица', 'value' => $block_show == 'none' ? null : $OrderCheckoutHelper->getActualFieldInfo('model', 'recipient_info', 'street_delivery', '[recipient_info][street_delivery]')['value']])
                ->label(false); ?>
        </div>
    </div>

    <div class="row giving_order_point_2_block" style="display: <?php echo $OrderCheckoutHelper->getBlockDisplay('giving_order_point_2_block');?>;">
        <div class="col-sm-4">
            <?php echo $form->field($model, 'recipient_info[house_delivery]')
                ->textInput(['placeholder' => 'Дом', 'value' => $block_show == 'none' ? null : $OrderCheckoutHelper->getActualFieldInfo('model', 'recipient_info', 'house_delivery', '[recipient_info][house_delivery]')['value']])
                ->label(false); ?>
        </div>
        <div class="col-sm-4">
            <?php echo $form->field($model, 'recipient_info[flat_delivery]')
                ->textInput(['placeholder' => 'Квартира', 'value' => $block_show == 'none' ? null : $OrderCheckoutHelper->getActualFieldInfo('model', 'recipient_info', 'flat_delivery', '[recipient_info][flat_delivery]')['value']])
                ->label(false); ?>
        </div>
        <div class="col-sm-4">
            <?php echo $form->field($model, 'recipient_info[zip_delivery]')
                ->textInput(['placeholder' => 'Индекс', 'value' => $block_show == 'none' ? null : $OrderCheckoutHelper->getActualFieldInfo('model', 'recipient_info', 'zip_delivery', '[recipient_info][zip_delivery]')['value']])
                ->label(false); ?>
        </div>
    </div>

    <div class="row to_terminal_city_block" style="display: <?php echo $OrderCheckoutHelper->getBlockDisplay('to_terminal_city_block');?>;">
        <div class="col-sm-12">
            <?php echo $form->field($model, 'shipping_company_delivery_city')
            ->textinput(['placeholder' => 'Город', 'value' => $OrderCheckoutHelper->getActualFieldInfo('model', 'shipping_company_delivery_city')['value']])
            ->label(false); ?>
        </div>
    </div>


    <div class="row address_delivery_block" style="display: <?php echo $OrderCheckoutHelper->getBlockDisplay('address_delivery_block');?>;">
        <div class="col-sm-12">
            <?php echo $form->field($model, 'recipient_info[address_delivery]')
            ->textInput(['placeholder' => 'Пункт выдачи заказов', 'value' => $OrderCheckoutHelper->getActualFieldInfo('model', 'recipient_info', 'address_delivery', '[address_delivery]')['value']])
            ->label(false); ?>
        </div>
    </div>

Answer 1

Provide the code, how to understand the reasons if there is no code?
UDP: The error was that only sm-classes were specified, and therefore everything ≥576px was not displayed as expected.