Is the offset correct. I know my mimaki is at .25. I never change it. I would also try slowing down the cutter as well. I've had 2 materials that would do this, both from stahls and it was always intermiten. I just stopped using those materials. I would also cut in shorter sections. maybe only 20" or so at a time. I never cut more than a 1000mm of material, usually 500mm