Hover State On Menu Buttons Stays On When Returning to the Slide

It's odd that the hover state would be programmed to get stuck even after revisiting a slide and the mouse is not hovering over it.

It's not programmed that way. The hover state is tied to the object, and if you select return to initial state on hover off,  it is programmed to stay in hover state until it senses the mouse moving off it. If you have moved to a different slide, it can't sense mouse movement. So when you come back to that slide, it is still waiting to sense the mouse leaving it. Objects don't know where the mouse is, only if it is moving onto or off of them.

The most unusual thing to me is why the buttons sometimes behave as I want them to but sometimes stay stuck in the hover state.

I never could get it to do that, so I can't help with that.

Variables are by far the most reliable method for this. I'm glad you got it going.