By installing BlueGriffon on Linux, we may have this problem in the system fonts of the software.
BlueGriffon®
The next-gen Web and EPUB Editor based on the rendering engine of Firefox
You need to edit 2 rendering parameters in Bluegriffon Tools > Preferences > Advanced > Advanced Configuration:
gfx.canvas.azure.backends
gfx.content.azure.backends
Change them from 'skia' to 'cairo'
Close the software and restart it.
Mattia
