I have seen such a problem, but on my side everything is done correctly and unfortunately there is nothing I can do.

What you need to do:
1. Add Log component, and enable Request Events.
2. Run the scene, and copy one url to the tile.
3. Write to mapbox support, attaching this url, and asking why the Static Tiles API doesn't work for me.
https://docs.mapbox.com/api/maps/static-tiles/

I'm not able to use a custom style created with mapbox studio within online maps 4.2.11.

I've been using tutorials and info but it has been impossible for us. Working just with other scenarios but not with custom styles... We see just a black area.

Thanks!