I got another set of cables, didn't help. I tried to fix it on software side and discovered that when I set both monitors on 60Hz, the lines disappear, yet when I put one on 60 and the other on 144Hz they reappear. Thus, cables are not the issue and neither is the monitor. I was thinking maybe the GPU cannot handle such amount of Hz, but it adds up to 205Hz. I have read articles about people running 240Hz panels off 1060, so I am really lost now. Maybe it has something to do with syncing different frequencies, I dunno. You got any idea, pal? Thanks in advance.