Hi,
and thank you for writing in!
After adding the product to the waiting list, in the product edit page you should see the number of users subscribed to the waiting list for that product (not the list of the user emails) as you can see here: https://docs.yithemes.com/yith-woocommerce-waiting-list/category/free-version-settings/
If the user email is not added to the waiting list, maybe something in your installation could conflict with the plugin and cause this issue.
In this case, to discover what is causing the issue you should isolate the plugin behavior; to do this, please, try to deactivate all plugins, leaving only WooCommerce and YITH WooCommerce Waiting List active, and see if the problem is solved. If so, try to activate them again, one by one, to see which one causes the issue.
If the problem isn’t caused by a plugin, try to activate a default WordPress theme (i.e:Twenty Twenty) and see if you have the same issue.
Also, if you have customized some files in your theme, please try with a fresh installation without any customization.
Please try this solution and let us know what’s the result.
