booleanContains gives false positive for another polygon in the inner ring

I am using Turf for a masterthesis about GeoSPARQL and during the preparation of a demo, I found a bug. In the demo, I'm testing which Geo objects are inside several others, with the example of my own country. In my country there's a small part of our country that's inside another part. This should say that "VlaamsBrabant" is not containing "Brussel", but the response is telling me it is containing it. The Geo data for these parts are available at https://gist.githubusercontent.com/dreeki/b0fd0ea3d75ea58adebab55c36566988/raw/428912374d67af18493444e769011a3c6fcfa87c/inner-ring-polygon.ttl

The polygons are visualised in the screenshot below.

Snippet of the code is the following:

import { Geometries as GeometryType } from '@turf/helpers';
import booleanDisjoint from '@turf/boolean-disjoint';

const firstGeometryObject: GeometryType = giveGeoObject(first.value);
const secondGeometryObject: GeometryType = giveGeoObject(second.value);
result = booleanContains(firstGeometryObject, secondGeometryObject);

and:

import { geometry, Geometries as GeometryType } from '@turf/helpers';
import * as Wkt from 'terraformer-wkt-parser';
import * as Terraformer from 'terraformer';

export const giveGeoObject: (text: string) => GeometryType = (text: string) => {
    const geoJSON = Wkt.parse(text);
    if(geoJSON instanceof Terraformer.Point || 
        geoJSON instanceof Terraformer.MultiPoint ||
        geoJSON instanceof Terraformer.LineString || 
        geoJSON instanceof Terraformer.MultiLineString ||
        geoJSON instanceof Terraformer.Polygon || 
        geoJSON instanceof Terraformer.MultiPolygon){
        return geometry(geoJSON.type, geoJSON.coordinates);
    }
    return null;
}

P.S. I love Turf, keep up the great work!

Start at the booleanContains entry point and reproduce the result with the linked inner-ring polygon Geo data and the example geometries. Trace how containment is determined for the nested polygon, then add a regression test showing that VlaamsBrabant does not contain Brussel and verify the corrected result.