Why does the video not start when I try to show VAST ads with the Roku SDK?

I’m having issues with ads when applying the following configuration:

playerConfig = {
    playback: { autoplay: true, muted: false },
    adaptation: { preload: true },
    key: m.global.configdetails.bitmovinSDK.key
    advertising: {
        adBreaks: [{
            tag: {
                type: "vast",
                url: getadUrl()
            }
        }]
    }
}

The function getadUrl() returns the following tag:

https://pubads.g.doubleclick.net/gampad/ads?iu=/21775744923/external/single_ad_samples&sz=640x480&cust_params=sample_ct%3Dlinear&ciu_szs=300x250%2C728x90&gdfp_req=1&output=vast&unviewed_position_start=1&env=vp&impl=s&correlator=

Any clue about what is wrong with that snippet?

There are two things that stand out to me:

  1. This line is missing a comma at the end, breaking the player config:
  1. To the best of my knowledge and understanding the ad configuration should be in the source config, not in the player config.

I hope the above helps narrow things down.