It might be that the font does not display specific chars correctly. Try to use another font.

Settings > Style Configurator... > Global Styles, Global override, Font Style: Font name: <try to set to another font, e.g. Courier New>

It might be that the font does not display specific chars correctly. Try to use another font.

Settings > Style Configurator... > Language: Global Styles, Style: Global override, Font Style: Font name: <try to set to another font, e.g. Courier New>
And check "Enable global font"