Strange behavior of the plugin WooCommerce Abandoned Cart Recovery

Hi,
we noticed a strange behavior of the plugin. It seems, that a bot keeps adding products to the cart, but without any e-mail adress, although we have made entering the email address a mandatory field before the checkout. And even stranger is, that this bot is using our server IP or sometimes US or chinese IPs (see screnshot). We keept deleting these entries but the problem remains and everyday new entries are generated.

Regards,

Andreas Otto