Gnosis Safe – How to Resolve Error in Step 3 of Safe-infrastructure

I am using Safe infrastructure for setting up gnosis-safe on Arbitrum-rinkeby.

However when running Step 3 (Add your chain info), my console throws the following error –

root@1fd61b7d8e90:/app/src# python manage.py loaddata chain.json
2022-02-02 07:08:19,819 [INFO] [MainProcess] Chain update. Triggering CGW webhook
2022-02-02 07:08:19,819 [DEBUG] [MainProcess] Converted retries value: 3 -> Retry(total=3, connect=None, read=None, redirect=None, status=None)
2022-02-02 07:08:19,821 [DEBUG] [MainProcess] Starting new HTTP connection (1): nginx:8000
2022-02-02 07:08:19,823 [DEBUG] [MainProcess] http://nginx:8000 "POST /v1/flush/some_random_token HTTP/1.1" 404 153
2022-02-02 07:08:19,823 [ERROR] [MainProcess] 404 Client Error: Not Found for url: http://nginx:8000/v1/flush/some_random_token
Installed 1 object(s) from 1 fixture(s)

I can confirm that when I run curl http://localhost:8000/cfg/api/v1/chains, my added ChainInfo does not shows up. Instead it returns Page not found (404) error.

For reference, this is my chain.json file –

[
    {
        "model": "chains.chain",
        "pk": 421611,
        "fields": {
            "relevance": 100,
            "name": "Arbitrum Testnet",
            "short_name": "arb-rin",
            "description": "",
            "l2": true,
            "rpc_authentication": "NO_AUTHENTICATION",
            "rpc_uri": "https://arb-rinkeby.g.alchemy.com/v2/Blablabla",
            "safe_apps_rpc_authentication": "NO_AUTHENTICATION",
            "safe_apps_rpc_uri": "https://arb-rinkeby.g.alchemy.com/v2/Blablabla",
            "block_explorer_uri_address_template": "https://testnet.arbiscan.io/address/{{address}}",
            "block_explorer_uri_tx_hash_template": "https://testnet.arbiscan.io/tx/{{txHash}}",
            "currency_name": "Ether",
            "currency_symbol": "ETH",
            "currency_decimals": 18,
            "currency_logo_uri": "chains/4/currency_logo.jpg",
            "transaction_service_uri": "http://localhost:8000/txs",
            "vpc_transaction_service_uri": "http://localhost:8000/txs",
            "theme_text_color": "#ffffff",
            "theme_background_color": "#000000",
            "ens_registry_address": null,
            "recommended_master_copy_version": "1.3.0"
        }
    }
]