Hi Heinrich,
Are you using OLMS (openlayers-mapbox-style) by any chance?
It looks like it's something missing in this lib in regards to our style.
If you load the location you hint at with MapLibre, you get the correct rendering
FYI, we will be shipping VectorTiles with the help of MapLibre, when the time is right (should be during this year).
We considered using OLMS, but ended up deciding not to use it because it is in essence a "one-man" lib, that always tries to catch up to latest changes from MapLibre/Mapbox.
And as our internal cartography department is using MapLibre to build our style JSON, it didn't make much sense to have any other framework at the wheel when rendering the product.
Cheers,
Pascal