Mail Alert "Notify me when available" not working for invited account

[Au Paradis du Jeu]

Hello,

I've used Mail Alert so customers could received a mail when a product became available again.

I've updated Mail Alert to 2.4.1 (my prestashop is 1.7.8.7) and now it's not working for invited account. (It work just fine if you are registered).

When I try to put an email adress on an out of stock product, I click on Notify me when available and nothing happens. (If I'm registered I have the "Request notification registered").

Can someone help me?

Thank you! (and sorry for the english)