Apple News: adding padding around text with background color

I can't figure it out. the "padding":10 either is ignored or the background extends to the left and right edge. See attached screenshot from the simulator.

            "role": "heading",
            "text": "News",
            "format": "markdown",
            "textStyle": {
                "textAlignment": "center",
                "backgroundColor": "#006FBA",
                "textColor": "#FFFFFF",
                "fontSize": 14,
                "lineHeight": 16,
                "fontWeight": "bold",
                "fontScaling": false
            },
            "style": {
                "backgroundColor": "#006FBA"
            },
            "layout": {
                "padding":5,
                "ignoreDocumentMargin": false,
                "margin": {
                    "bottom": 15,
                    "left":30,
                    "right":30
                }
            }
        },
        {
            "role": "heading",
            "text": "News",
            "format": "markdown",
            "textStyle": {
                "textAlignment": "center",
                "backgroundColor": "#006FBA",
                "textColor": "#FFFFFF",
                "fontSize": 14,
                "lineHeight": 16,
                "fontWeight": "bold",
                "fontScaling": false
            },
            "layout": {
                "padding":5,
                "ignoreDocumentMargin": false,
                "margin": {
                    "bottom": 15,
                    "left":30,
                    "right":30
                }
            }
        },
        {
            "role": "container",
            "components": [
                {
                    "role": "heading",
                    "text": "News",
                    "textStyle": {
                        "textAlignment": "center",
                        "backgroundColor": "#006FBA",
                        "textAbove": "1",
                        "textColor": "#FFFFFF",
                        "fontSize": 14,
                        "lineHeight": 16,
                        "fontWeight": "bold",
                        "fontScaling": false
                    },
                    "style": {
                        "backgroundColor": "#006FBA"
                    },
                    "layout": {
                        "padding":5
                    }
                }
            ]
        },