After inserting of a new or selection of an existing text you cannot increase text size with top screen menue “text”. Both functions bigger or smaller make the text smaller. The only correct working way I found is in menu Parameter/Titel by choosing font and fontsize
Further to this topic, it is also not possible to make the text/title smaller or bigger with the animation. In the before and after screen the text just changes at the same time, one can not start with a small title and end with that title ie 3 times bigger after the animation…