Why are there trees inside my building?

MapsIndoors as default uses a custom Mapbox MapStyle to access certain features on the Mapbox map. This Mapbox MapStyle includes showing trees in 3D, but sometimes these trees end up inside your building. To avoid this it is necessary to use your own custom Mapbox MapStyle that hides trees on a global level, potentially only at the zoom levels where you will see MapsIndoors data instead of Mapbox data.

How to then use your custom Mapbox MapStyle is described in

Using a Custom Mapbox MapStyle