Hello,
after about 2h of debugging I have found the problem.
The trigger used by JoomSEF was not launched correctly.
This was caused by installation of some SEF patch module which was conflicting with JoomSEF. I had to make a hack in the code to get around this.
So this was not a configuration or JoomSEF problem, but conflict with other piece of code, that was not even listed mambots or component. Please, be carefull about installing such patches.
Anyway, the meta show correctly now. I would appreciate, if you could buy a support time for this event.
www.artio.net/en/e-shop/support-services
Best regards,
ARTIO Support Team