BBPress not sending emails out on topic reply

Forum Test Topic URL:
For some reason, when a reply is made, no email notification is sent to the people that are subscribed. Can you please take a look? Support access is open.
BTW: WordPress email working fine with the WP Mail SMTP plugin.

EDIT: The email notification is working fine, I did not see the checkbox that was unchecked, I thought it was checked. Is there anyway to keep that subscribe checkbox checked by default?