The lower part of my screen is updated one frame earlier than the upper part. I was able to isolate the error to the HDMI output of my laptop. The screen or cable is not broken, as I don't get these errors with other connected devices. I am assuming it is some hardware defect. Does anyone know what it could be and how I could fix it? Here are a few pictures that show the problem: pixelfed

Solved: Ok, it seems to have been a software problem. That had to do with the sync. I have installed ubuntu on the laptop for now and everything works again. Some update seems to have shot something. I am now using a LTS version.