Yes, an example would be helpful as this would narrow the diagnosis.
Here are steps to allow you to print a job that will show the defect more clearly.
From the device UI
1. Press Machine Status button
2. Touch Tools tab
3. Touch Troubleshooting
4. Touch Support Pages
5. Touch Repeating defects page
6. Touch Print (or similar) button on same page.
7. Inspect the prints for defects.
White lines on this product are caused by three possibilities. These are listed in order of most common/easiest to fix.
1. Dirty LPH assy (easy fix).
2. Developer housing issue
3. Bad LPH assy
You can usually correct #1 yourself. Number 2 and 3 require the machine to be serviced, and probably parts replacements.
A forth possibility would be a bad fuser, but if this were the case, the white line would not be very clean or consistent and toner would rub off the page with your finger.
Also, make sure that you choose the proper paper type (weight) at the UI when loading the paper into the tray. This is very important for proper paper handling and copy quality. (Failing to do this step can also cause toner to rub off or smear).
Cleaning the LPH. This video shows you how to clean just the cyan, but you want to perform the same steps for all stations.https://youtu.be/wyEW9PhC_d8
If this does not resolve the issue, you will want to place a service call to have the machine repaired.