LibreOffice does not list all styles of my font

I have a font called Capsa which has the following variants:
Roman: Capsa-Roman.ttf
Bold: Capsa-Bold.ttf
Italic: Capsa-Italic.ttf
Patterns: Capsa-Patterns.ttf
Vignettes: Capsa-Vignettes.ttf
Swashes: Capsa-Swashes.ttf

The problem I’m facing is that LibreOffice is falling back to Vignettes as the “Normal” style instead of using “Roman”. This causes the font to appear like this (Text is “Alpha”):

Inspecting the character styles, I can see that “Italic” and “Bold Italic” styles are correctly used by Writer. However, “Bold” is also falling back to “Vignette”. How do I ensure that correct fonts are picked up?

All fonts are installed correctly as fc-match is able to find them.

This is tdf#35538