VSCode not running task on folder open

I'm using TypeScript and constantly having to start the tsc-watch task manually. According to to the Blog VSCode v1.30+ can automatically run tasks when a folder is opened but this is not working for me (v1.33.1) - I open my folder and no task is running.

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558
    // for the documentation about the tasks.json format
    "version": "2.0.0",
    "tasks": [
        {
            "type": "typescript",
            "tsconfig": "tsconfig.json",
            "isBackground": true,
            "problemMatcher": [
                "$tsc"
            ]
        },
        {
            "type": "typescript",
            "label": "TypeScript Compiler Watcher Thingy...",
            "tsconfig": "tsconfig.json",
            "option": "watch",
            "problemMatcher": [
                "$tsc-watch"
            ],
            "runOptions": {
                "runOn": "folderOpen"
            }
        }
    ]
}

BTW: Also tried this extension and it also did not start the task.