LaserJet Pro MFP M281fdw printing colored lines on entire page

[aj237769]

Recently our printer started printing multi-colored horizontal lines on the entire page.  The original document contents can be seen very faintly through the lines but as  you'll see in the attachments, the prints are worthless. I found a similar post from a couple of years ago and someone suggested printing an 'engine' test page by opening and closing the front door 5 times.  I did that, and one of the images below represents that test page - same thing on both sides.   

Any thoughts? 

  

[Valsimot]

Are toners genuine or non-genuine?

Toner levels are normal or very low?

Both non-genuine toners or overridden toners can cause that.

[aj237769]

Thanks for replying.  According to the HP Smart app and the printer display the toner levels are near 75%.  We've also never replaced them so they are genuine.  That said, my wife said she may have messed something up recently when trying to get something to print.  I pulled all of the toners out and re-installed them, and that may have cleared things up.  I will be testing today.