Created attachment 138539 [details] Screenshot SUMMARY Line graphs tend to have white/empty spots inside them. You may take a look at the attached screenshot SOFTWARE/OS VERSIONS Linux/KDE Plasma: 5.11.20-300.fc34.x86_64 (available in About System) KDE Plasma Version: 5.21 KDE Frameworks Version: 5.81 Qt Version: 5.15.2
Ah, we fixed this one in Plasma 5.22 already.