How to make div, following cursor to overlap custom scrollbar?

I have a few divs, which follow cursor and cursor itself is hidden. I also have custom scrollbar, created via basic -webkit-scrollbar thing. When I hover my custom cursor over my custom scrollbar it goes under it, but I want it to go over scrollbar. How do I do that? z-index seems to have no effect

I tried implementing z-index thing, but it did not work