"Ah, I see. Well, the solution will be hard-working, but it is an easy one to look upon.
You have unallowed characters in your tooltips, which makes them stretch over the boundaries. Take a look at those two cubes: it can be seen from "distance", but it can't be seen when you open and edit your tooltips.
Remake all the tooltips that are causing troubles. Just delete everything, and write down what you want.