In context of https://www.8theme.com/topic/gdpr-plugin-stays-on-top-of-mobile-nav-menu/#post-369134
You wrote
In case you don’t use fixed footer on your web-site then the fix you found will not give you any issues and could be left for your case.
But in fact it does break the checkout/cart page with separated layout. Changing the z-index back to 1 makes it as before.
So my proposed solution doesn’t really fix the issue.