Could you send us a test link to your site or provide a code to reproduce the issue ? Have you not set any z-index CSS value to the button that overlaps the ktmenu submenu ?
I was just looking your demo pages and came across this error on add new contact page.
The solution to the error is to lower the z-index value of the add button. But I don't know if this value triggers a different region. I leave the link to the page where the error is found below. look out the page