Suscribers Alert does not work

Hi there,

I set the plugin up, and everything looks fine, admin email is working too when someone is suscribed to a product.

The issue is the most important thing, when my product is available again, the alert is not working and the client does not get any notification.

I’ve set https://es.wordpress.org/plugins/wp-mail-smtp/ this plugin as well and it’s been configured properly (I’ve done tests) to ensure that emails are working, but suscribers doesn’t get any alert anyway.

Any help?

Thanks.