you might already know this issue, but just in case you don’t… I have just installed “Fedora Linux 38 KDE Plasma (20230911600)” and found a very weird behavior of the installer and regional options - it does not set regional settings properly.
In the installer, I have set American English as the system language. Then I have set my location to Prague and in the following page I have set my keyboard layout to English (US) - Default, I have set my password to 123456, expecting the US keyboard.
Behavior when logged in: there is no keyboard layout configured in the settings, actual keyboard is Czech (QWERTZ) which was default for Prague. Numbers and date format is set for US. Timezone is correctly set to Prague. My password is +ěščřž (which is 123456 on czech keyboard) - tested in Konsole with sudo.
Behavior on login screen: English (US) keyboard acts as Czech (QWERTZ) keyboard. It seems that for some reason it was overwritten by installer. Date and time format is set for czech.
I attach screenshots from the installation and running systems. Let me know if you need any assistance. Thank you.