Implementing own TileServerProvider

I am using HERE Maps SDK Lite Edition Version 4.7.3.0, which gives the possibility to ad a RasterLayer with an own TileServerProvider implementation (see documentation).

I edited the given example by exchanging the SimpleTileServerProvider with my own implementation.

      RasterLayer myCustomLayer = new RasterLayer("CUSTOM_LAYER",
          17,
          1001,
          new TileServerProvider() {
             @NonNull
             @NotNull
             @Override
             public String provideURL(long x, long y, long zoom) {
                return "myURI";
             }
          });

When adding this RasterLayer to my MapView, provideURI is called, but only 0 values are passed to the parameters of provideURI. What is getting wrong here?

In my production code I did not enter 17 for parameter maxZoomLevel directly, but took this value from a function. But this function did return 0 instead.