[xwiki-users] Color theme switching to default!

Greetings dear XWiki users! I have installed XWiki 8.4.4 on CentOS 7.3, with Tomcat and MySQL support. I have integrated the site with Active Directory, so any user can use Windows credentials to login and have the XWiki user automatically created (without the need of registration). In the starting “Home” Wiki, i have created a new Color Theme to use. Every new user logins to this wiki, retains the Color Theme i chose for the wiki and all is good. However, when i created a new Wiki (Wiki2 let’s say) and have chosen the new “Global” Color Theme to use for this Wiki too, only root can login to that wiki and retain it. All other new users, once they login to this wiki, have their color theme switching to default! What am i missing? Thank you all for any assistance! Best regards, Petros