If you are cutting thick media, even with laminating, maybe 9U know would not work well. 09U45 knife can cut up to 150~200 micron only. For thicker media, please use 15U knife.

Also please check,

–  if blade holder is fixed well and if knife is installed well into the bearing of the blade holder

–  if blade holder’s bearing is not smooth enough. then pls replace it.

–  if blade itself is worn out. then pls replace it.