Hi @sofy, thanks for getting back to me. It's difficult to post an imagine, but i will try and explain better. 

I am creating multiple forums under a few category's on a new site. Each forum has different access rights, with some of the forums only being accessible to registered users / members. 

To do this, I am using the access rights controls on the right hand side of the individual forum settings page, changing Guest access from say "read only" to "no access". 

Once i save the changes, and navigate back to the dashboard > forums > forums page, the forum that I have just changed the Guest access rights to has disappeared entirely from the list of forums. It is also no longer visible on the front end. 

I don't have this problem when i change any other user rights, only the Guest User. 

Hope that makes more sense. 

Thanks