SC9 - theme - widget heading no bold

Hello,
I imported my SC8-project to SC9. What I experience: the bold headlines of the widgets of my dashboard now are in normal letters, even though the theme says bold f?r the font.
No matter how I change it, they will not get bold. The theme I generated as a copy of SC7-bluesky and adjusted backgrounds and font.
When I change to e.g. SC9-theme, the changes are there, but when changed back: again no bold heading.

Any idea?