Backorder issues

Hello,

I am having trouble making a counter order.

It does not allow me to add more than one quantity to an order.

I have added a product to Woocommerce

Then I have added two Inventories using ATUM Multi Inventory with this configuration

Manage Stock: yes
Stock quantity: 0
Allow backorders ?: Allow

But when trying to order from the store, the following happens;

https://paste.pics/9LMUV

You can also see the error in this link

https://demo.multi-inventory.stockmanagementlabs.com/h8agt39euqr1icd/product/man-t-shirt-blue-2/

I hope I have explained, I appreciate your comments.

Regards

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