Permission issues with Docker installation (unable to write/read/edit, can delete)

@wwe and @KarlF12:

Could you please confirm that everything looks OK in this docker-compose?

services:
  nextcloud-db:
    image: mariadb:latest
    container_name: nextcloud-mysql
    restart: unless-stopped
    command: --transaction-isolation=READ-COMMITTED --binlog-format=ROW
    volumes:
      - ./nextcloud-mysql/db:/var/lib/mysql
    environment:
      - MYSQL_ROOT_PASSWORD=<pass>
      - MYSQL_PASSWORD=<pass>
      - MYSQL_DATABASE=nextcloud
      - MYSQL_USER=nextcloud
      - MYSQL_LOG_CONSOLE=true
    networks:
      - nextcloud-net

  nextcloud-app:
    image: nextcloud:latest
    container_name: nextcloud-app
    restart: unless-stopped
    networks:
      - nextcloud-net
    ports: ["8080:80"]
    environment:
      - MYSQL_HOST=nextcloud-db
      - MYSQL_DATABASE=nextcloud
      - MYSQL_USER=nextcloud
      - MYSQL_PASSWORD=<pass>
    volumes:
      - /media/uxb3/F/nextcloud/:/var/www/html
    depends_on:
      - nextcloud-db

networks:
  nextcloud-net:

I have not created /media/uxb3/F/nextcloud/ yet.