Try to do the following
1. Edit the file woodmart/inc/options/class-sanitize.php and replace the following line
$val = wp_kses_post( $val );
with this one
$val = wp_kses( $val, woodmart_get_allowed_html() );
2. And put this code snippet to the functions.php file in your child theme
function woodmart_get_allowed_html() {
return apply_filters(
'woodmart_allowed_html',
array(
'br' => array(),
'i' => array(),
'b' => array(),
'u' => array(),
'em' => array(),
'del' => array(),
'iframe' => array(
'width' => true,
'height' => true,
'src' => true,
'title' => true,
'frameborder' => true,
'allow' => true,
'allowfullscreen' => true,
),
'a' => array(
'href' => true,
'class' => true,
'target' => true,
'title' => true,
'rel' => true,
),
'strong' => array(),
'span' => array(
'style' => true,
'class' => true,
),
)
);
}
.
