PushPins not visible on iOS devices with rounded corners, the home indicator

I'm struggling with pushpins not showing on devices with rounded corners, the home indicator (iPhone 12 Pro Max for instance). Every other devices including iPads are displaying my pushpins (truck/flag...). See by yourself below The map is centered on them.

This is driving me crazy.

I'm using the bing maps V8 Ajax control inside a WKWebView control.

pseudo code:

// Vehicles  
vehiclelayer = new Microsoft.Maps.Layer();  
vehiclelayer.setZIndex(3);  
this.map.layers.insert(vehiclelayer);  
...  
var pushpin;  
var pushpinOptions;  
  
pushpinOptions = {  
   icon: imageBase64,  
   title: label,  
   visible: true,  
   anchor: anchor,  
  };  
var location = new Microsoft.Maps.Location(latitude, longitude);  
pushpin = new Microsoft.Maps.Pushpin(location, pushpinOptions);  
vehiclelayer.add(pushpin, index);  

The results:

iPad

iPhone 12 Pro Max

What could be the root cause of this problem?
Is there a debug mode for the control to be able to diagnose the issue?