Hello Cees,
I see that issue. The custom map marker icon does not display correctly on the map. You can try to use this custom CSS code to fix the issue with the custom icon.
img.leaflet-marker-icon {
margin-left: -12px;
margin-top: -41px;
width: 25px;
height: 41px;
}
I've escalated this issue to the development team to fix it in the next update.