I've set the User Locale in our Domain to Slovenian and while it does update the machines locale to Slovenian there seems to be an underlying bug, because machines still won't show the correct characters in some programs. I have to manually switch the system locale into a random region, restart, then switch back to Slovenian and restart again in order for everything to work correctly.
There seems to be a similar issue with "Recently added apps". If I enable it via group policies, it is shown as off in the Start settings menu, but it will still display the recently added programs. I have to remove the group policy and turn it off manually for it to work. (Computer Configuration > Policies > Administrative Templates > Start Menu and Taskbar > Recently added (Enabled)

