I retracted my previous statement, it was incorrect.
I don't know the answer to your question though, so it is probably still a service tech matter with NVM settings if it is indeed just on fax reports.
If you select the physical button that says Language to the right of the touch screen, it will do as stated above...
But...
<login to the copier as admin> and go to Machine Status > Tools > Device Settings > General > Language / Keyboard Selection and change it there, even though it is the identical screen, it will apply to everything system wide.
But if yours is all in one language including the configuration report, yet the fax confirm is in another, then it would be a tech because something is broken