Ink gets carried over to subsequent sheets
More than likely your maintenance kit roller has been impacted with ink and is not applying enough lubricant to the drum. You can replace the maintenance kit and run cleaning procedures a couple of times to allow it to clean up.
Now the other issue is if you are using a third party ink stick. By that I mean non xerox brand ink sticks. I have seen those cause that problem more often than not.
Pull out the maintenance kit and see if the large roller, which should be a off white, is black.
Exacly what is happening is your maintenance kit puts a very thin film of silicon oil on the drum so that the ink does not adhere to the drum more than normal. When that roller becomes blackened, it isn't very effective and you get some of that residual imaging.