Stock alert variable products

Hi,

I have been using the WooCommerce Product Stock Alert plugin by WC Marketplace for about 2 years, and it has always worked ok.

Today I noticed that in the products with variations, the field for the customer to leave the email and to be notified when the product is back in stock is no longer appearing.

In simple products it appears, but in products with variations it does not.
If both variations are sold out, it does not appear.
If only one is sold out, this one doesn't appear either.

I leave some examples:
Single product sold out:
https://www.morethanbeautystore.com/produto/paulas-choice-c15-super-booster/

Product with one of the variations sold out:
https://www.morethanbeautystore.com/produto/paulas-choice-resist-anti-aging-clear-skin-moisturiser/

Both variations are sold out
https://www.morethanbeautystore.com/produto/paulas-choice-10-azelaic-acid-booster/?customize_changeset_uuid=2aad96ea-6b21-4975-8e2a-f43d9e3b3403&customize_autosaved=on&customize_messenger_channel=preview-3

Thank you so much for your help,
Patrícia

The page I need help with: [log in to see the link]