ngraham added a comment.
Thanks @zren. Moving "Use locale default" to the middle position makes everything work perfectly. I tested the upgrade use cases and the combobox is always pre-populated with the correct value. REPOSITORY R120 Plasma Workspace REVISION DETAIL https://phabricator.kde.org/D19230 To: ngraham, #plasma, Zren, #vdg Cc: plasma-devel, jraleigh, GB_2, ragreen, Pitel, ZrenBot, lesliezhai, ali-mohamed, jensreuterberg, abetts, sebas, apol, mart