Shibboleth Developers

Hi,
I use Shibboleth SP 2.3.1 to protect a Java application that performs 
authentication by reading attributes from header.
The application allows a user to authenticate using the parameter "cf" that 
reads from header. Shibboleth SP retrieves the parameter from Shibboleth IdP 
and passes it to the application. The application reads the header and logs 
the user.
Unfortunately, authentication only works locally. Java application running 
under JBoss and is protected by shibboleth with apache and mod_jk. Apache 
passes the parameters in the header only if I use the browser locally and not 
pass them if I try to authenticate from another pc. What could it be?
Thanks