I confirm the error also with Italian Timezone.
Happened to me with the latest version: https://files.kde.org/neon/images/neon- ... 1021-amd64.

I tried also using United States timezone.

update:
I have probably solved after some try recreating the usb with unetbootin.
Also i have used OEM installation this time because i have UEFI.

Apparently you need to install the English version of the system, but with the right time zones and the necessary keyboard languages and keyboard layouts. Then already in the established system to change its language, I hope this is possible and this solution will be simpler.

Then the problem is solved! selection and installation of the preferred language in the system in the settings section "User Preferences" - "Localization".

Summary
For me it seemed that the system set is not enough widgets, there is no necessary set of my preferred widgets Oxygen "out of the box", they were not found from the proposed for installation. I'm trying an alternative possible solution http://cdimage.ubuntu.com/kubuntu/relea ... 04/beta-1/
When installing problems like this is not found. And my preferred widgets are suggested, which is called "out of the box".

Sorry about this, tracking it in this bug
https://bugs.kde.org/show_bug.cgi?id=392713