I think there's a problem with the notifications and Gantry 5.

For some reason, when I see the notifications icon with an unread reply, I click on it and it doesn't load the post. Instead, it switches to my Gantry Home template rather than using Default.

I guess you are aware that Gantry 5 has two types of templates, one for the home page and one for the rest of the pages.

I have added to this post the credentials to one account that has 1 unread notification for you to try it. Simply login and go here: http://www.simracinghub.com/forum