Why is the image blocking the navigation?

Question

css

Trying to make another template, I can’t figure out why the image from the content gets on the menu (it’s impossible to click on the links from the menu, when you hover over the mouse - the mouse does not change, as usual when you hover over the link).
Tried to set z-index: 999; menu (for the image it is 99) - does not help.
Please help.
Image code:

.main-content_right img {
  position: relative;
  z-index: 99;
  top: 43px;
}

Menu code:

nav {
  padding-top: 25px;
}

nav ul {
  display: flex;
}

nav ul li a {
  text-decoration: none;
  text-transform: uppercase;
  color: #4d4d4d;
  padding-left: 30px;
  font-weight: 500;
}

Answer 1

Check the positioning of the menu, z-index does not work with , but in general, yes, a piece of code would be handy position: static