When you want to edit some text just by selecting it and dragging and dropping it, it will be actually copied in new place instead of being moved. Old text will simply remain in original place. Reproducible: Always
I started working on this, it's due to the overriding behavior of insertFromMimeData
Change suggested https://phabricator.kde.org/D14177
Fixed in https://phabricator.kde.org/D14177