Pad-A-Cheek Quattro Air Mouth Opening?

I just received a pad a cheek mask liner for my quattro air. It feels great, however I am unsure on how big the opening should be. I cut a couple of slits at the top of the hole like the manual said, but the liner still completely covers my mouth. Only my nose pokes through.

I researched the matter, but can't figure it out. Is it supposed to cover up your mouth? The airflow also seems restricted in a weird way. If I cut it, should I make two slits at the bottom or just open up the hole wider?

Thanks