Not connecting to ws://127.0.0.1:8000/graphql-ws

[MathCryptoDoc]

I am testing the standard docker compose file for polkadot with three modifications:

• START_BLOCK=18000000
• Substrate RPC is "wss://rpc.ibp.network/polkadot" (both in docker-compose.yml and explorer-ui-config.json)
• Disabled the substrate-node in docker-compose.yml

Docker compose starts fine and I can go to the website http://localhost:8080/local. Blocks are appearing but only new ones. The old ones are not available, despite that the harvester processes them fine.

It seems that the connection to ws://127.0.0.1:8000/graphql-ws is not established. It keeps on connecting when I check its status in the website.

Is there something I can do to debug?

Files are attached:
docker-compose.yml.txt
explorer-ui-config.json.txt

[MathCryptoDoc]

If you use the public ip of the server in explorerWsUrlArray instead of localhost, it works.