Hi, I'm having the same problem. about 50% of my subs are OK but the other 50% range from having a few vertical lines to looking exactly like your screenshot.
I have tried many of the suggestions I've seen online like turning off wifi and bluetooth and adjusting the USB slider in the camera's ascom driver control panel but all to no avail.
I've seen someone online (https://www.cloudynights.com/topic/587286-asi1600mm-cool-stark-vertical-lines-every-few-frames/) who was having the same sort of issue. A ZWO employee told them that the camera was faulty (something about soldering I think?) and needed to be returned for replacement.
Alan
1600-4.jpg