You inherit from Windows installation default settings on a the very first connection for each user.
You will need to assign a full remote desktop for each user and:
- use a GPO to force some settings to apply to all
- or click on the button below to force your style and date format setting to all of your newly created users.
Please note this will not work if a session was already opened after creating a new user.
Example: changing the System Locale from English US to English UK fixed the issue for existing users.