Currently some themes have all-caps for some textelements on the master.
I can't locate where I can toggle between all-caps, and a regular typeface.
Select the text and go to the menu Format > Font > Capitals (last one in list) and select None. (I may be off a little with the spelling as I translated this back to English.)
Format > Fonts > Capitalization > All Caps is the right way to make all caps. It seems there is no other shorter way to do it.