Ion menu button error

Ionic Framework Ionic Angular
1

I am developing an app using Ionic 5, Angular, and Cordova.
I put the ion menu button on the top left of the home screen, but when I enter another screen and return to the home screen, the button moves slightly down and then up again.
This phenomenon only appears on ios

<ion-header mode="md" class="main-header">
  <ion-toolbar>
    <div class="header-inner">
      **<ion-menu-button></ion-menu-button>**
      <ion-title><img src="assets/images/header-logo-linkon.svg" width="25%"></ion-title>
    </div>
  </ion-toolbar>
</ion-header>

ion-menu-button{
z-index: 10;
}