Change strike out html
Adjust the HTML structure used for strike-through pricing.
add_filter('advanced_woo_discount_rules_strikeout_price_html', function($html, $original_price, $discounted_price, $is_variable_product, $initial_price_html, $separator){
$initial_price_html = str_replace('<small class="woocommerce-price-suffix">inkl. MwSt.</small>', '', $initial_price_html);
$html = '<del>'.$initial_price_html.'</del>'. $separator .'<ins>' . $discounted_price . '</ins>';
return $html;
}, 10, 6);