https://cgit.kde.org/plasma-desktop.git/commit/kcms/fonts/kxftconfig.cpp?id=88ae0b60b81325b838aae2c48b790b81f810b903 The KXftConfig::applyExcludeRange actually set the "less_eq" things. I need to find a change from "less" to "less_eq" to prove my theory. But unluckily the log just backs to 2014.3 while 13.1 was released in 2013 But I can still download the tarball from OBS to verify.