Go into Feed mode and open up the cover. There's a little ramp a few inches out on the black outfeed panels that tends to lift the leading edge of the print slightly. If there is a curl in the paper, the ramp can sometimes lift it enough to swipe the heads. Watch as edge of the paper feeds over that ramp, look at the edge of the paper near the suction recesses just past the rollers to see if it's lifting towards the heads there. One cure is just to feed out media, and stop when you don't see any more lifting, which is usually when the curled leading edge reaches the far side of the ramp. Or you can roll out a foot or so of media and de-curl it on an old core, then feed it back in. May or may not be your actual problem, but the location of the swipes kind of suggests that's the case. Also, have heard of cases where too much suction can problems even worse than not enough.