Error when creating Order and Invoice for product sale with WooCommerce variant

[sptechcue]

I have a client that uses Woocommerce Connector, it synchronizes stock, orders, customers, all good so far.

But there is a snag with an order you had recently, I recreated it on my test machine and give you an example:

You have 2 items with 2 variants each:

Shoe 1: VARIANT: Color Red VARIANT: Size 8
VARIANT: Color Red VARIANT: Size 9
Shoe 2: VARIANT: Color Blue VARIANT: Size 8
VARIANT: Color Blue VARIANT: Size 9

---

When a customer buys in the same order 2 shoes of the same model, but different sizes:
Shoe 1: VARIANT: Color Red VARIANT: Size 8
VARIANT: Color Red VARIANT: Size 9

When the Sales Order (SO) and the sales invoice are created, only one of the two variants appears in the 2 items.

SALES ORDER

SALES INVOICE

But when checking the woocommerce log it does import correctly.

I have tested it in ERPNext v13, v14 and v15 and in all of them it is the same.
Maybe someone can give me a hand.
Regards