CosmosDB Emulator - Losing data after deleting Docker Container

Question

I am building a CosmosDB Emulator container via a docker-compose.yml file.

version: '3.4'

services:
  cosmosdb:
    container_name: cosmosdb
    image: "mcr.microsoft.com/cosmosdb/linux/azure-cosmos-emulator:latest"
    tty: true
    mem_limit: 2G
    cpu_count: 2
    environment:
      - AZURE_COSMOS_EMULATOR_PARTITION_COUNT=10
      - AZURE_COSMOS_EMULATOR_ENABLE_DATA_PERSISTENCE=true
    ports:
      - '8081:8081'
      #- '8900:8900'
      #- '8901:8901'
      #- '8902:8902'
      #- '10250:10250'
      #- '10251:10251'
      #- '10252:10252'
      #- '10253:10253'
      #- '10254:10254'
      #- '10255:10255'
      #- '10256:10256'
      #- '10350:10350'
    volumes:
       - vol_cosmos:/data/db

volumes: 
  vol_cosmos:

I then generate some data in it via the CosmosDB Emulator Explorer. However, if I delete the container I lose all the data, even though the container uses the specified volume, and the volume is not deleted ever.

Either I don't understand how volumes work, or something else is wrong, but I am looking for a way to persists the data even after deleting the container. A new one should just use the volume with the specified name if it exists, or create a new one if it doesn't, right?

The data stays intact after container and/or OS restarts. It just doesn't persist after deleting the container.