Stacking problem with third party menu plugin

Hello,
I’m using Max Mega Menu and implemented it as a Shortcode. The z-index is set above all the other elements on the webpage, but I think the Visual Composer classes are interfering with my CSS, so it doesn’t work and appears underneath.

I know you don’t provide support for any type of third party plugins, but maybe you can help me with that issue regarding the Visual Composer.
Here’s a screenshot: https://imgur.com/a/bTVL8vE

Thank you in advance!

Ticket