<div class="ui tab" data-tab="inventory">
    <h3 class="ui dividing header">{{ 'sylius.ui.inventory'|trans }}</h3>
    <div class="ui segment">
        {% if product.simple %}
            {{ form_row(form.variant.onHand) }}
            {{ form_row(form.variant.tracked) }}
            {{ form_row(form.variant.version) }}
        {% endif %}
    </div>
</div>

<div class="ui tab" data-tab="inventory">
    <h3 class="ui top attached header">{{ 'sylius.ui.inventory'|trans }}</h3>
    <div class="ui attached segment">
        {% if product.simple %}
            {{ form_row(form.variant.onHand) }}
            {{ form_row(form.variant.tracked) }}
            {{ form_row(form.variant.version) }}
        {% endif %}
    </div>
</div>

Fix UI in Product's inventory tab
Fix UI in Product's inventory tab