Say the template is called about_body.html
You have to rename the template ANYTHING different because phpbb does not seem to update if you change anything in the template.
So say I have a custom page and I'm linking the page to the about_body.html template. When I make a single change to the template it does not update the page UNLESS I change the template name and link the new php document to the new template name.

It doesn't even update even if you restart WAMP server.