Thank you for using our services.
Unfortunately we do experience some issues with this. If you have had enabled localization on an earlier stage and set default culture the redirect works. However if you have enabled localization and change default language on a later stage it will keep loading the original culture interface on login. If you set default culture ar on a fresh project the redirect will work.
We are not able however to fix this in the upcoming SP. So the only available workaround would be to either to set the return url of the login form in the ~/Sitefinity/Login.aspx
to be the desired URL:
Note you will have to edit this once you go to production
. Or each user can set their preferred culture on the My Preferences page (see attached image).
the Telerik team