Change font for specific characters within a shape

I have to change the font in a text Class of a shape. In Corel Version 2022 and before this worked properly. Now when using Version 2023 this does not seem to work anymore for specific fonts. Here a example, how I do this:

This should change the second Character in ActiveShape to an other Font:

ActiveShape.Text.Story.Characters(2).Font="Bookshelf Symbol 7"

ActiveShape.Text.Story.Characters(2).Font="ITC Zapf Dingbats"

But if I change the font for example to Arial, then this works.

Has anybody an idea, why specific fonts does not work or a solution for this?

Best Regards

Klaus