In JS API v3.19 there appears to be a bug which requires the JSON style file for a Mapbox GL style to include a 'layout' property, even if it is empty. The absence of a 'layout' causes the map to crash. We've only seen this issue when the layer type is 'line' but it may also occur for other layer types. Manually adding ("layout: {}") to root.json fixes the problem but this is tedious when there are many layers.
Will this be corrected in future versions of the API? We have not tested with v3.20 directly, as we encountered the problem when adding a VectorTileLayer to Portal v10.5.0 which uses JS API v3.19 and our testing has been limited to Portal so far.
