Breeze normal is fine.
Relevant icon is system-suspend
Can't reproduce, system-suspend (the two half circles ontop of each other) is fine.
Created attachment 114427 [details] showing the bug. Actually this issue is available for a long time for me, for several plasma versions. plasma: 4:5.13.1.1-1 (Debian unstable) breeze-icon-theme 4:5.47.0-1 (Debian unstable)
Created attachment 114428 [details] Working properly I wiped my icon and plasma theme caches, tried with Breeze (using dark system colorscheme), and Breeze Dark, as well as using Oxygen as regular iconset. Worked just fine in all instances.
How I wipe icon and plasma theme caches?
I deleted everything in cache, but this did not helped :( killall plasmashell rm -f .cache/plasma* plasmashell also tried to relogin and change the icon theme to oxygen (the icons didn't got updated at all) other icons in the systemtray got updated. So maybe this plugin has it's own icon cache?
Git commit 4bda8ec0b74b4993feebc2e3998fc5a19e92834d by Kai Uwe Broulik. Committed on 17/08/2018 at 09:50. Pushed by broulik into branch 'master'. Fix style sheet for 22-22-system-suspend Turns out this icon had a hardcoded color in it which wasn't the case for the full size icon used on my high dpi system. Thanks Sandro Knauß for helping investigate this M +- -- src/desktoptheme/breeze/icons/system.svgz https://commits.kde.org/plasma-framework/4bda8ec0b74b4993feebc2e3998fc5a19e92834d