Hello Pierre-Jean,
Thank you for writing.
This is normal behavior and it can be obtained with the standard MS WinForms controls as well.
In order to localize the controls on the form, I would recommend you to follow the steps demonstrated in this help article:
https://msdn.microsoft.com/en-us/library/y99d1cd3(v=vs.71).aspx
I hope this information helps. Should you have further questions I would be glad to help.
Regards,
Dess
Telerik by Progress
Telerik UI for WinForms is ready for
Visual Studio 2017 RC! Learn more.