Hide menu on mouse exit

I'm trying to build a menu that operates in Lectora the same way it does on a website: the menu appears when the mouse enters the word Menu and it disappears when the mouse exits the menu. The menu consists of a filled box for the background, text boxes with hyperlinks, and lines to separate the text boxes. The menu appears when the mouse enters the text box containing the word Menu. What doesn't work is the menu disappearing when the mouse exits the background box. Lectora seems to think that a mouse over of a text box that sits above the background is the same thing as a mouse exit of the background shape, so the menu disappears before a user can click on a hyperlink.

Any ideas?