MF731Cdw getting vertical black bar when scanning from top feeder.

Hello, would appreciate any help.

I have a  MF731Cdw getting vertical black bar when scanning from top feeder, but only on every other copy job. If I copy a 10 page job, no vertical line, but every other copy job, I get a vertical bar like line from top to bottom of page. 

This only happens when scanning from the top feeder and only happens every other print job.

I get no lines when scanning from bed or on normal print jobs.

Thanks!