@Sunny I had the same issue, it was caused by fractional scaling for me.
In System Settings > Display & Monitor, I had the scale at 115% and would constantly see those transparent horizontal lines. Some KDE apps were particularly bad with this, notably Kate, Kwrite and Konsole.
Not really a fix, but for me changing the scaling to 120% “fixed” it. So I suggest you play around with the scaling.
@Sunny I had the same issue, it was caused by fractional scaling for me.
In System Settings > Display & Monitor, I had the scale at 115% and would constantly see those transparent horizontal lines. Some KDE apps were particularly bad with this, notably Kate, Kwrite and Konsole.
Not really a fix, but for me changing the scaling to 120% “fixed” it. So I suggest you play around with the scaling.