If lines appear down copied pages but printed pages sent directly to copier render as intended, it could be due to scratched scanner glass which can cause lines or streaks on copied pages.
If there are lines appearing on copied pages, but not on printed pages sent directly to the copier, the issue is most likely caused by a scratch on the scanner glass. References:
https://www.pacificoffice.com/how-to-fix-lines-on-copier/