So when restarting the game - I usually have to do it along with my router restart to make a faster reconnect - I get some visual bugs, most of them more minor.
Starts with things like the smite damage in that's usually displayed in your buff bar is not displayed, ends with the following:
Areas that were in sight (due to champion sight, wards or whatever) in the moment disconnect/close the game stay "visible" after reconnecting/starting the game. So the fog of war on these areas (both on-screen and map) is as if there was a ward, but in reality there is no sight. This makes it very irritating, when you go there and all of a sudden someone/something pops out of an area you thought you have sight on.
Already repaired the installation, didn't change.