Good evening Bruno and welcome back!
Thank you for reaching out to us.
We are sorry to hear about the tickets not being sent on your site. Yikes!
I would love to help you with this topic.
The tickets are normally sent based on the settings in place at the bottom of the Events -> Settings -> Tickets screen. Most specifically, they are triggered by the order status of your choice.
If that still does not work for some reason, you can have the system send tickets from any chosen email address by simply installing, configuring and testing the following plugin: https://wordpress.org/plugins/easy-wp-smtp/
Using a real SMTP server with authentication will bypass the built-in WP mail functionality altogether.
Please make sure you configure and test the settings using the plugin’s built-in tool. This typically cures the problem.
As for re-sending the tickets, you can do so by going in the WooCommerce order and clicking on the Actions menu.
Let me know how that goes.
Best regards,
Geoff B.