When the members enter their e-mail, the password reset e-mail cannot be sent, it gives an error. In new records, it says e-mail has been sent, but it does not reach.
wpForo doesn't send any emails, it queues it to Wordpress core.
Use some smtp plugin for WP with logging and see what happens.
In any case not related to wpForo. Login/Register/Emails are all handled by WP.
The issue is not related to wpForo plugin. wpForo doesn't send the emails, it's a function of WordPress core and your hosting service.
Please check all these points carefully: https://wpforo.com/community/faq/not-receiving-automatic-replynotificationconfirmation-emails/#post-5344