Can not change chord text attributes once entered

I score music for autoharp play. One of the things common in doing this is indicating if a chord is for melody or accompainment. To do this, I need to make certain chords larger and bold.

When trying to do this, the chord changes back to its original text attributes when I finish editing it. These are chords that I have put into the score, not some one else's.

I am using the text formatting buttons on the bottom of the screen to do this. Am I doing something wrong, or is this a bug?