Does any of you use object styles

Hi

I seem to have issue with the the Object Styles saved reverting back to the default font. I've created a shortcut for Franklin Gothic Book 12pt as it is the font used within our firm. The problem is, every now and then it seems to jump back to Arial 12pt after I export it in PDF (only after I export it in PDF). It's at random and also sometimes only on the 1 out of 5 pages. Anyone else have this problem?

Is there a way to change the default font in Corel Designer?