Mat not sticky enough i use photo reposition spray.
Silhouette mat moving around.
Mat moving around sounds like the blue drop handle on the right is up or it is not places under the rollers quite right.
My silhouette 3 is still cutting in the wrong place up on the mat at the top left even though it is set for the 12 12 cutting mat in the silhouette studio.
I actually purchased an a3 non brand cutting mat from ebay found the tacky to be just enough.
To get more wear out of your cutting mat turn it around and use the bottom half too.
This can really prolong the life of your cutting mat.
It cut in the right place one time and then reverted back to cutting in the wrong place.
So instead of always putting the end with the arrow into the machine turn it around and put the opposite end in that means the arrow will be pointing toward you.