Liberation Sans Narrow font is not rendered correctly on Qt5

We would like to use this font. We used it on Qt4 but when going to Qt5, it seems the font is not rendered correctly.

See screenshot and example code. The example code shows Liberation Sans and Liberation Sans Narrow displayed side by side. The narrow font is actually wider than the non-narrow.

I think the install is generally okay because firefox can render it correctly using code like '<p style="font-family: liberation sans narrow">Text Here</p>'.

There is a post about a similar problem here, but that's all I could find: http://lists.qt-project.org/pipermail/interest/2014-October/013948.html

Any debugging ideas also very welcome. I did check with strace as in that post, that the font is being open()ed at least.

Is Qt having an issue with the narrow size font?