Why doesn't fullscreen work in chrome-85 on ios?

Question

JavaScript

when you click on the fullscreen button, the function works:

// check if fullscreen mode is available
  if (document.fullscreenEnabled || 
    document.webkitFullscreenEnabled || 
    document.mozFullScreenEnabled ||
    document.msFullscreenEnabled) {
    
    // which element will be fullscreen
    var iframe = document.querySelector('#player_block');
    // Do fullscreen
    if (iframe.requestFullscreen) {
      iframe.requestFullscreen();
    } else if (iframe.webkitRequestFullscreen) {
      iframe.webkitRequestFullscreen();
    } else if (iframe.mozRequestFullScreen) {
      iframe.mozRequestFullScreen();
    } else if (iframe.msRequestFullscreen) {
      iframe.msRequestFullscreen();
    }
  }
  else {
    alert( 'Your browser is not supported')  //показывает это
  }

caniuse says chrome should be able to: