Please try to add a line

# -*- coding: utf-8 -*-

as the first line of your source file. I would like to see, if the character encoding is 
set correctly. All text drawing is done by the QScintilla editor widget. However, it might 
be initialized incorrectly, although I never saw such an issue on any of my systems 
(Windows 7 and 10, various Linux and macOS).

In which version did it work? What was updated since then?