MarkerOptions.anchor doesn't affect on position

package.json:
```
...
"@ionic-native/core": "^5.0.0",
"@ionic-native/device": "^5.21.6",
"@ionic-native/google-maps": "^5.27.0-beta-20200630",
"@ionic/angular": "^5.0.4",
"cordova-browser": "6.0.0"
...
```
using cordova browser.
```
this.map.addMarker({
position: {lat: this.lat, lng: this.lon},
icon: {
url: '../../assets/icon/eye.png',

size: {
width: 32,
height: 32
}
},
anchor: [16, 16]
})
```
the marker appears at the same place in any anchor