... to remote from a remote machine ...
this should be login from a remote machine
Looks like cookies are enabled in your browser. Try disabling cookies and see if it works.
Also try clearing out the browser cache of your second browser instance, before accessing the application
The same happens even if the second instance is a Firefox instance.
As far as I am aware, it isn't possible. The JBoss caching mechanism doesn't/can't distinguish between where the authentication request comes from - e.g. a new browser session vs. new page request vs. EJB call. You can try setting the timeout to 1 second, which would effectively force every page request to hit the LoginModule again, or to 0 seconds which would cause every authentication request (including EJB calls) to hit the login module.
I decided to set the DefaultCacheTimeout to 0 and just ignore the credential
check when the user has already logged in.
Thank you for your answers.