See the image in attachment Reproducible: Always
Created attachment 99046 [details] Screenshot
Looks like a regression, 2.9 seems 'stable', but maybe that was just an accident.
Git commit b4e68ae57b335c1d35b12111583d613af6080b0d by Boudewijn Rempt. Committed on 18/05/2016 at 11:18. Pushed by rempt into branch 'rempt-opengl-check3'. M +3 -1 libs/ui/kis_filter_manager.cc http://commits.kde.org/krita/b4e68ae57b335c1d35b12111583d613af6080b0d