I honestly don't know what pressure you need to use, try 5 or 6, make sure your blade depth is around 5 or 6, and speed is medium or a bit slower.
Some really thick paper needs to be cut with the multi cut setting, meaning that the blade runs around the image 2 or 3 times.
Glitter paper is inherently difficult to cut and often needs multi cut, and then the mat needs to be cleaned because glitter gets everywhere.
There a lady named Megan and her site is "Above Rubies Studio" do a web search and she has a free cutting guide about different papers, blade, pressure and speed settings. There is also a free App from I-Tunes that has her cuts. Just follow the links on her web page.