Created attachment 113411 [details] screenshot See the screenshot taken on Arch Linux.
Upstream bug fixed in Qt 5.11.
Are you sure Nate? I use Qt 5.11.1 and the problem persists.
Darn, you're right. I didn't see this because it only starts looking bad after restarting plasmashell. PLASMA_USE_QT_SCALING=1 is no help. Looks like we've got no option except to covert it to use controls from QtQuick 2.0 or PlasmaComponents.
Nevertheless an upstream bug.
If it's an upstream bug, it's different from the one that I thought it was that was fixed in 5.11. Can you locate the bug?
*** This bug has been marked as a duplicate of bug 396725 ***