PointGroup | Set Point Grouping for 3D Instance Segmentation | Machine Learning library

What you're doing in your Loaded event is quite weird. I would not recommend doing that, as it will wreck your bindings. If the reason you're doing that is so that the Name property is shown in your ComboBox, you should rather use a DataTemplate. Something like this:

Make sure you understand How do I return the response from an asynchronous call?

In your case, when you assign your pointGroup a Layer Group from your pointCoordinates array, the latter is still empty, i.e. none of your AJAX requests had time to complete and push anything into it.

By default JavaScript is not reactive, so when your AJAX requests eventually complete, they do push something into pointCoordinates, but that does not update pointGroup.

A very easy solution however would be to build your pointGroup in outer scope as a Layer Group beforehand, and to add the GeoJSON Layer Groups that you build in your AJAX requests callback directly into that pointGroup, instead of using an intermediary plain array.

When you add them to the Layer Group, Leaflet will also update the map accordingly.

Here's a simple implementation to calculate the value of the desired y-axis tick for each facet: