I’m not sure if this is a result of the update to plasma 5.5.3 or if it’s something else, but I’m now seeing visual corruption behind the text labels for desktop icons. If I move the icons then it goes away until my next boot.
That looks like a driver related issue.
What GPU do you have, and what drivers are you using for it?
That was my first thought, but I wanted to make sure nobody else was seeing this. I have a GeForce GTX 960m and I’m using the NVIDIA proprietary drivers (361.18). Since those are beta drivers I wouldn’t be surprised if it’s my driver that’s the issue.