[otrs] no ticket lock and no FollowUp Notify after followup message

Hello, I've found strange problem and I can't find the right cause. :-/ After followup email comes to OTRS, it finds right ticket and place itself into ticket as a new article. The problem is, that owner desn't get any followup notification and ticket also don't get locked. Howcome? Settings: Queue: followup possible Agent: Followup Notification->Yes Best Regards, Alex