Why +Body with theme switching disabled?

[Ulodesk]

At work, we often make a copy of a master template and then customize the copy for the needs of the specific job. I keep theme switching disabled in our master (and copies), which I thought disabled themes altogether. Our paragraph styles are all custom.
I was asked to change the font for all styles for one project that's just rampling up, from Arial to Calibri. When I later opened the template again to make some additional changes, I kept finding +Body instead of Calibri in the font field of the font dialogue box. I find this very frsutrating; I want to see the font name there; this has not previously been a problem.
We use Office 365 on a company network, if that makes a difference; the templates from which I am working are stored on my local machine.


Thanks.