Please check out the screenshot below where you can see all of the CSS comes from the template six and there has no custom CSS that comes from our theme or we overwrote.
http://prntscr.com/ljqgxd
http://prntscr.com/ljqh90
It can be an issue of WHMCS Bridge Plugin. Because the WHMCS comes into the WHMCS Bridge Plugin.
Best Regards,
ThemeLooks Support Team