Even with theme switching disabled, every document/template uses a theme and has +body and +heading fonts as well as theme colors.


In the font list, the theme fonts will show up with heading or body in parentheses after them.


i.e., Calibri (Heading) Cambria (Body) instead of Calibri and Cambria.



You are not required to use those but they are built into built-in styles. You can modify the styles to use the actual fonts.


Is this not what you are experiencing?