When you hover over a star system in the galaxy map, and then close the galaxy map, the tooltip does not go away. In order to make it go away you need to open the galaxy map and ensure that you don't hover over a star system before closing it.

It would be nice if the tooltip closed when closing the galaxy map.

it does this for other stuff to, fix please

You can fix this by hovering your cursor over any kind of thing that gives a similar type of tooltip as the system map, as only one of those tooltips are open at any given time.
For example, if you hover over the map button on bottom right, a tooltip will appear saying right click to hide galaxy info (right clicking that button makes it smaller), this tooltip should get rid of any other tooltips that look similar to it.

Chinese needle snakes will get rid of this by biting out your eyes