Unable to display captions / subtitles on videos generated through API

Hello,

I have been trying for some time to add captions / subtitles from an SRT file through the API, but although the video generates without any errors, I am not seeing captions at all. Does anybody know what I may be doing incorrectly? I have hidden sensitive data like URLS.

Thank you in advance!

Here is a copy of my API request:

{
    "timeline": {
        "background": "#000000",
        "tracks": [
            {
                "clips": [
                    {
                        "asset": {
                            "type": "video",
                            "src": "https:\/\/XXX.XXX\/williams.mp4",
                            "volume": 0
                        },
                        "start": 0,
                        "length": 5
                    },
                    {
                        "asset": {
                            "type": "video",
                            "src": "https:\/\/XXX.XXX\/williams.mp4",
                            "volume": 0
                        },
                        "start": 5,
                        "length": 5
                    }
                ]
            },
            {
                "clips": [
                    {
                        "asset": {
                            "type": "audio",
                            "src": "https:\/\/XXX.XXX\/music.mp3",
                            "effect": "fadeInFadeOut",
                            "volume": 0.200000000000000011102230246251565404236316680908203125
                        },
                        "start": 0,
                        "length": 10
                    },
                    {
                        "asset": {
                            "type": "audio",
                            "src": "https:\/\/XXX.XXX\/output1.mp3",
                            "volume": 0.8000000000000000444089209850062616169452667236328125
                        },
                        "start": 0,
                        "length": 10
                    }
                ]
            },
            {
                "clips": [
                    {
                        "asset": {
                            "type": "caption",
                            "src": "https:\/\/XXX.XXX\/output1.srt",
                            "font": {
                                "color": "#ffffff",
                                "size": 50,
                                "lineHeight": 1.5,
                                "family": "Montserrat ExtraBold",
                                "stroke": "#000000",
                                "strokeWidth": 1
                            },
                            "background": {
                                "color": "#000000",
                                "padding": 20,
                                "borderRadius": 10,
                                "opacity": 0.59999999999999997779553950749686919152736663818359375
                            }
                        },
                        "start": 0,
                        "length": "end",
                        "position": "center"
                    }
                ]
            }
        ]
    },
    "output": {
        "format": "mp4",
        "size": {
            "width": 1080,
            "height": 1920
        }
    }
}

Issue solved. Was just the clip order