OK very green to this and trying to understand what it’s doing.
I set up a page for the forum and pulling data in with [bbp-forum-index]
The template I selected is the same as the main page and other pages on the site (note lack of sidebars) but when I select that same template for the Forum page it seems to ignore it and I end up with a sidebar.
I di not set up the website initially so don’t know what changes were in place but find it strange that this pages shows different when using the same template.
Here is the link, if you look at the other pages you’ll notice the difference.