I got the same issue as a couple of years ago. Maybe now i can find someone who can help me.
I got an NCR 7197 POS Printer with an Edgeport usb to serial adapter. As soon as the edgeportdriver and the ncr pos ready driver is installed the printer prints about 30 lines with one single letter Z.
It's pretty annoying. Everytime the POS System goes into standby and starts again a bunch of paper is wasted.
Had the same issue a couple of years ago with a different system and a different printer. I don't know if i ever solved it or simply bought an other printer back then.
I installed onld 5.14 and new 6.05 drivers but nothing changed.
Here is my Post from 2014: https://www.digi.com/support/forum/42927/ncr-7197-starts-printing-stuff-soon-edgeport-driver-active
It seems like i am not the only one with that problem.