Which version of Muse are you using?
Is the menu composition made by your using native muse widget or is it a third party?
Looking at your site I think you should reconsider the choice of the widget.
In your case a drop-down accordion widget shall be more effective - Answer to drop-down accordion widget overlaying content below.
What are your thoughts on this?
I started of with an accordeon widget, but I had some troubles with it, not doing what I wanted or messing up the layout.
Not very sure what the issue was in general, been too long since I switched it for the other widget, which was working and didin't have to think on the accordeon troubles anymore.Off course I was not aware of the troubles after which I encounter now.
I will try to dig in the accordeon again to see if I can fix the issue which I encounter now with the other widget.
But still strange that when the widget - which i'm using now - is hidden the boxes don't work in the area it was shown before...
Thx for the support, for now I will leave it as it is and try to do it again in a later stage.