Try to add the following PHP code snippet to the child theme functions.php file to fix this
function woodmart_show_categories_dropdown() {
$args = array(
'hide_empty' => 1,
'parent' => 0
);
$terms = get_terms('product_cat', $args);
if( ! empty( $terms ) && ! is_wp_error( $terms ) ) {
?>
<div class="search-by-category input-dropdown">
<div class="input-dropdown-inner woodmart-scroll-content">
<input type="hidden" name="product_cat" value="0">
<a href="#" data-val="0"><?php esc_html_e('Select category', 'woodmart'); ?></a>
<div class="list-wrapper woodmart-scroll">
<ul class="woodmart-scroll-content">
<li style="display:none;"><a href="#" data-val="0"><?php esc_html_e('Select category', 'woodmart'); ?></a></li>
<?php
if( ! apply_filters( 'woodmart_show_only_parent_categories_dropdown', false ) ) {
$args = array(
'orderby' => 'id',
'title_li' => false,
'taxonomy' => 'product_cat',
'use_desc_for_title' => false,
'walker' => new WOODMART_Custom_Walker_Category(),
);
wp_list_categories($args);
} else {
foreach ( $terms as $term ) {
?>
<li><a href="#" data-val="<?php echo esc_attr( $term->slug ); ?>"><?php echo esc_attr( $term->name ); ?></a></li>
<?php
}
}
?>
</ul>
</div>
</div>
</div>
<?php
}
}