Plugin suddenly not working?

When I installed the plugin back in March, the permalink helper works really nicely to redirect my old permalinks to the new ones.

But now, it doesn’t seem to work. Links like this one http://www.fafafoom.com/2011/05/12/academy-of-arts-universitys-graduate-fashion-show-2011-review/ should’ve redirect to http://www.fafafoom.com/academy-of-arts-universitys-graduate-fashion-show-2011-review/, but it’s not.

Please help,
Musank

https://ww.wp.xz.cn/plugins/change-permalink-helper/