Openlayers 6 offline local vector pbf files "Unimplemented type: 6" error

I'm trying to convert OpenStreetMap data (osm.pbf file) to "z/x/y.pbf" folder/file structure and show the map offline using Openlayers 6 and Ionic.

What I did so far is:

1. Downloaded osm.pbf file (https://download.geofabrik.de/europe/netherlands/flevoland.html)
2. Used Maperitive to open osm.pbf and used generate-mbtiles [minzoom=0 maxzoom=16] to generate mbtiles
3. Used mbutil (https://github.com/mapbox/mbutil) with mb-util --image_format=pbf input_folder output_folder command. After this I end up with pbfs inside proper folder structure - so far so great.
4. Show pbfs with openlayers (note that I'm using Ionic so here's some Angular code)

this.map = new Map({
layers: [
        new VectorTileLayer({
          declutter: true,
          source: new VectorTileSource({
            format: new MVT(),
            url: 'http://localhost:8100/assets/downloaded-osm-pbfs/{z}/{x}/{y}.pbf'
          }),
          style: createMapboxStreetsV6Style(Style, Fill, Stroke, Icon, Text)
        })
      ],
      target: 'map',
      view: new View({
        center: [0, 0],
        zoom: 2
      })
    });

After this I end up with "Error: Unimplemented type: 6" once I try to view map inside browser.

Interesting thing is that if I use https://openmaptiles.com/downloads and download mbtiles from there and do steps 3-4 (in step 3 I just do extra step and uncompress pbfs because openmaptiles gzip's the files) everything is displayed properly, but problem here is that openmaptiles provide 14 zoom levels and I need 16 zoom levels.

Any idea how to overcome this issue? Any help will be appreciated!