text "Multiplexer" is poorly rendered in side-bar of "MkvToolnix 10.0.0.0" "MkvToolnix GUI"

0.4.10-RC-30-g51a70dc gcc dbg linux.
MkvToolnix 10.0.0.0 from rapps, the main app "MkvToolnix GUI" renders the text poorly in the sidebar. E.g. the word "Multiplexer".

Observed result
0.4.10-RC-30-g51a70dc__sidebar_multiplexer.png

Expected result
2k3sp2_Sidebar_Multiplexer.PNG

The bug has not been introduced by the font metrics changes, it existed also before, but until now I found it to be too subtle to even mention it. But ros is constantly improving, so my nitpicking must improve as well.