StackOverflow https://stackoverflow.com/questions/56985354/why-tasks-are-stuck-in-none-state-in-airflow-1-10-2-after-a-trigger-dag/56987794

docker-compose.yaml

version: '3.1'
services:
    webserver:
        image: puckel/docker-airflow:1.9.0-3
        environment: 
            - LOAD_EX=n 
        volumes:
            - ./assets/dags:/usr/local/airflow/dags
        ports:
            - "8080:8080"
        command: webserver
        healthcheck:
            test: ["CMD-SHELL", "[ -f /usr/local/airflow/airflow-webserver.pid ]"]
            interval: 30s
            timeout: 30s
            retries: 3