Memory limit (4GB) error when using wc_get_orders

Memory limit error when my custom code uses “wc_get_orders” recommeded by WC to search in the WC database.

Error: “class-wc-order-data-store-cpt.php”, “line”: 129

I found the line 129 in class-wc-order-data-store-cpt.php, it is:
‘order_key’ => get_post_meta( $id, ‘_order_key’, true ),

• I use “wc_get_orders” with some specific details in that orders.
• The database has a few thousand orders. It is not big.
• Memory limit at 4GB still generates the error.

The error occurs WC is searching it’s own WC database using the WC recommended code “wc_get_orders”.
I discussed with developers and they recommended to contact WC, they do not have other solution and WC documentation has no reference to this situation.

Thank you.