Ionic 4 - Fixed content work differently on ios / android?

I want a fixed content that is behind a scroll content. For this goal, the HTML looks like

  <div slot="fixed" class="header-fixed">
    <h1>This header is fixed</h1>
  <div class="content-on-top">
      Lorem ipsum dolor sit amet, consectetur adipiscing elit.
      Proin sit amet tristique ex. Aenean bibendum rutrum sollicitudin.

and this is the scss

  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  width: 100%;
  height: 200px;
  background: red;
  z-index: 9;

  width: 80vw;
  margin-top: 100px;
  background: blue; 
  height: 150vh;
  position: relative;
  z-index: 99;

The first image is on android and work very well

But on ios, the fixed content is already on top…

Any advices ?

You cannot set z-index for fixed content.

Also, you can create a scrollable area inside fixed content, so you can control z-index of child element: