Wp All Import Duplicates Alone

I typically import daily jobs with wp all import + wp all import wp job manager plugin. But one problem that I figured out is sometimes the wp all import, imports 2 records twice.

As you can see, in my CSV we have only one line with that reference:

But the plugin, creates twice, as you can see:

I use the reference to avoid duplication, and I use this function too:

<?php

function dont_duplicate_skus( $continue_import, $data, $import_id ) {
	
    $sku = $data['ref'];
    
    global $wpdb;

    $product_id = $wpdb->get_var( $wpdb->prepare( "SELECT post_id FROM $wpdb->postmeta WHERE meta_key='ref' AND meta_value='%s' LIMIT 1", $sku ) );
	
    if ( $product_id ) {

        return false;

    } else {

        return true;

    }
}

add_filter('wp_all_import_is_post_to_create', 'dont_duplicate_skus', 10, 3);

?>

How can I fix this?

Regards

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