[Hack](https://sourcefoundry.org/hack/) has a higher underscore position and so may not be affected by this geany bug.
Thanks @ashjoubert that did the trick.
Here's a quick easy guide:
`sudo apt install fonts-hack-ttf` Open Geany. ``` Edit > Preferences > Interface Fonts, Editor, "Hack Regular" Apply, OK. ```
if you decide to stay at an older ver.of geany
@xzhh it's not "if you" it's what the distribution ships as stable from there repos. For things like this it highlights that model is flawed but unfortunately that's how it is (if you stick with stock standard stuff for security support).