Created attachment 183273 [details]
Kate with lines

SUMMARY
I believe that randomly (I don't remember changing it in the system) thin vertical lines started flashing on my screen, I noticed that it doesn't happen while playing games.

STEPS TO REPRODUCE
1. setting your monitor scale to 115%
2. open Kate and maximize it

OBSERVED RESULT
Vertical lines on window

EXPECTED RESULT
These vertical lines don't appear

Linux/KDE Plasma: 6.15.6-arch1-1 
KDE Plasma Version:  6.4.2
KDE Frameworks Version: 6.16.0
Qt Version: 6.9.1

ADDITIONAL INFORMATION
I noticed that the issue was caused by my monitor's scale. At 115% (which I didn't set myself), the issue occurs, but when I set it to 125% or 100%, the issue doesn't happen.