I’ve noticed that every time I try to change the font type and size in the TextEditing tab of the Preferences, doing a ‘font search’ (from the font panel) it doesn’t change the font, but the Preference window closes. So I have to repeat the path, going manually to the font I need.
I can’t reproduce this - the Preferences panel doesn’t close when I try this. The text area of the Preferences panel does need the focus for it to change font, though, so if you search for a font in the Font panel, try clicking back into the text area of the Preferences before clicking on the font in the font panel to change it.