Setting of Font style doesn't work properly in Font Marker Symbology

[jimmyhenne]

What is the bug or the crash?

When choosing a Font Marker Symbology for a point layer, you can choose Font style by a dropdown menu. Depending on the Font family, you can choose bold, italic, narrow and combined styles, but some style don't affect the actual appearing. E.g. for the Arial Font family only black and narrow style work properly - the other choosable styles change nothing.

There is a similar dropdown for font style in the 'Labels' settings in the layer properties and this works, but font marking in 'Symbology' doesn't.

Steps to reproduce the issue

• Import WFS: e.g. https://geoservices.krzn.de/security-proxy/services/wfs_verb_freizeit
• Load Layer:: gis:kvie_radknotenpunkte
• Choose a Font Marker for Symbology with 'RADKNOTENPUNKTNUMMER' as Character(s)
• Call dropdown menu for 'Font style' and choose 'bold' (Fett) and see if that actually changes the font style

Versions

QGIS version | 3.20.1-Odense | QGIS code revision | 1c3c5cd6 -- | -- | -- | -- Qt version | 5.15.2 Python version | 3.9.5 GDAL/OGR version | 3.3.1 PROJ version | 8.1.0 EPSG Registry database version | v10.018 (2021-04-02) GEOS version | 3.9.1-CAPI-1.14.2 SQLite version | 3.35.2 PDAL version | 2.3.0 PostgreSQL client version | 13.0 SpatiaLite version | 5.0.1 QWT version | 6.1.3 QScintilla2 version | 2.11.5 OS version | Windows 10 Version 1607   |   |   |   Active Python plugins | canvas_clipperDataDrivenInputMaskflurstueck_finderGeoCodingImportPhotosMemoryLayerSavermmqgisqfieldsyncQuickOSMquick_map_servicesdb_managerprocessing

Supported QGIS version

• [X] I'm running a supported QGIS version according to the roadmap.

New profile

• [X] I tried with a new QGIS profile

Additional context

No response

[jimmyhenne]

I have noticed that when using interface translation Deutsch, you can do a workaround by editing the Font Style (Schriftartstil) with the Expression String Builder and type 'Bold' or 'Italic'. But that doesn't work with American English..