Custom site name not woking for artio-sef1.2.zip!!The setting can see below,but the tags page title not showing with Custom site name"joomla templates"!

I'm using joomseo to rewrite the page title,and disable the artio joomsef title rewriting!I have enable a Section as default homepage!Then the homepage title become"Section name/site name",and the tag page title become"tag/Section name/site name",now i want the tag page showing as "tag/site name",so i set Custom site name to "site name",but after that the tag page title still showing as "tag/Section name/site name",is this a bug??