Existing voltas do not obey text style changes
1. Add a volta to a score.
2. Style / Text... / Volta, change something. The original report concerned vertical offset; you can also change the font (e.g., to MuseJazz), or make the font size huge, or any change that will be clearly noticeable.
3. Click OK.
Expected result: volta numbers change to new style.
Actual result: nothing.
If you then add a new volta, it will follow the new style, but it seems voltas only respect the style in effect when they are first added to the score and ignore further changes.