Cognos not setting the correct product/content locale via SDK

[ora1001]

Version: Cognos 10.2
Security: Custom Security Provider using Motio

When entered http://localhost/cognos10 the login screen comes up. This is all did by the Motio. Even if the user's locale is setting to German in our application, for some reason when the user logged in the folders are have displaying in english. This happening very much randomly.. for some users it displaying properly and for some it defaulted to english.  All the user membership came under our custom security provider motio namespace. When the user log in, the custom security provider checked the validity of the user and get the user information like locale etc from a different application via restful service using java sdk. Our cognos admin suggested to delete browser history and cache . but it did not worked also that way.

any help is appreciating