The material is buckling up on the heater and catching the upper part of the dryer unit when exiting, the ink is not dry so it smudges. We usually see this on some materials if you don't feed it out enough before printing starts, temp settings are too high, the platen has some goo on it so the backing sticks to the platen. You can try to lower the curing temp by 4-5 degrees, increase vaacuum a tad and/or use takeup. This has helped for us in many cases but it usually only happens on certain materials that we don't print a lot on. Good luck!