add_filter( 'woocommerce_structured_data_product_offer', function( $offer, $product ) {
    if ( is_array( $offer ) && isset( $offer['@type'] ) ) {
        if ( $offer['@type'] === 'Offer' ) {
            $offer['priceCurrency'] = 'TRY';
            return $offer;
        }
        if ( $offer['@type'] === 'AggregateOffer' ) {
            $offer['priceCurrency'] = 'TRY';
            if ( isset( $offer['offers'] ) && is_array( $offer['offers'] ) ) {
                foreach ( $offer['offers'] as $i => $inner ) {
                    if ( is_array( $inner ) ) {
                        $offer['offers'][ $i ]['priceCurrency'] = 'TRY';
                    }
                }
            }
            return $offer;
        }
    }
    if ( is_array( $offer ) ) {
        $keys = array_keys( $offer );
        $is_list = $keys === range( 0, count( $offer ) - 1 );
        if ( $is_list ) {
            foreach ( $offer as $i => $maybe ) {
                if ( is_array( $maybe ) ) {
                    $offer[ $i ]['priceCurrency'] = 'TRY';
                }
            }
            return $offer;
        }
        $offer['priceCurrency'] = 'TRY';
    }
    return $offer;
}, 999, 2 );

Yukarıdaki kodu functions.php'ye ekleyip, cache'leri temizleyip, https://validator.schema.org/ adresinde url'yi bir daha test edebilir misin?