I also added Turkey and Spain

Are you certain these large close buttons aren't interfering with the OnClick actions?
Well, these large buttons are on the overlay frame which are later in the frame sequence and if they are interfering with the hotspots on other frames then they aren't interfering all the time. So, while not 100% certain, I'm quite confident that this isn't the issue.

How does it give you another working entry to the zones?
If you have an overlay open and you click over, say, Zone I, then click again, Zone I's overlay appears. If you enter from the French Zone it's overlay appears. That's two ways in as I see it. All other routes result in a non-click.