Video registered, but Discord webhook is never sent

[itsnanobug]

Hello,
Thank you for this software.

I'm helping out some friends with a podcast for custom keyboards.

They'd like to post a video when they upload the latest podcast to their YouTube channel (it's quite niche).
So I've tested with my own YouTube channel.

I can get FeedCord to register the video when I use the xml formatted YouTube link.

But it never sends the Discord webhook.

I've tested the webhook with

curl -H "Content-Type: application/json" \
-d '{"content": "Test message"}' \
https://discordapp.com/api/webhooks/XYZ/XYZ

As shown here:

Here's my docker compose file:

services:
  feedcord:
    image: 'qolors/feedcord:latest'
    container_name: feedcord
    user: "1002:1002"
    volumes:
      - ./appsettings.json:/app/config/appsettings.json

Here's my appsettings.json file:

  GNU nano 7.2                                                                                             appsettings.json                                                                                                       
{
  "Instances": [
    {
      "Id": "Test News Feed",
      "YoutubeUrls": [
        "https://www.youtube.com/feeds/videos.xml?channel_id=UCvbt0Qm-t5mc7YgIOE-blAg"
      ],
      "RssUrls": [
        ""
      ],
      "Forum": false,
      "DiscordWebhookUrl": "https://discordapp.com/api/webhooks/XYZ/XYZ",
      "RssCheckIntervalMinutes": 1,
      "EnableAutoRemove": false,
      "Color": 8411391,
      "DescriptionLimit": 250,
      "MarkdownFormat": false,
      "PersistenceOnShutdown": true
    }
  ],
  "ConcurrentRequests": 40

I know the check interval is low, but it's just for testing right now.

I'm sure just missing something, I just can't tell what it is.

Can someone point me in the right direction?