Immutable & Fantom not working since 1.3.3

[themetalfleece]

Description

We're having trouble with the Immutable & Fantom since version 1.3.3 (and maybe other chains with special finalized behavior have this issue).

Configuration test_nodecore.yml:

server:
  port: 9090
  metrics-port: 9093

upstream-config:
  upstreams:
    - id: drpc-immutable
      chain: immutable-zkevm
      connectors:
        - type: json-rpc
          url: https://immutable-zkevm.drpc.org
    - id: official-immutable
      chain: immutable-zkevm
      connectors:
        - type: json-rpc
          url: https://rpc.immutable.com

    - id: drpc-fantom
      chain: fantom
      connectors:
        - type: json-rpc
          url: https://fantom.drpc.org
    - id: official-fantom
      chain: fantom
      connectors:
        - type: json-rpc
          url: https://rpcapi.fantom.network

Running v1.3.2:

docker run --rm -it   -p 9090:9090 -p 9093:9093   -v "$PWD/test_nodecore.yml:/app/test_nodecore.yml:ro"   -e NODECORE_CONFIG_PATH=/app/test_nodecore.yml   drpcorg/nodecore:1.3.2

It works:

curl -s -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"eth_getBlockByNumber","params":["latest",false],"id":1}' http://localhost:9090/queries/fantom

{"id":1,"jsonrpc":"2.0","result":{"baseFeePerGas":"0x3b9aca00","difficulty":...

curl -s -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"eth_getBlockByNumber","params":["latest",false],"id":1}' http://localhost:9090/queries/immutable-zkevm

{"id":1,"jsonrpc":"2.0","result":{"baseFeePerGas":"0x31","blobGasUsed":...

However, starting from version 1.3.3, and including the latest main (using make run), we get:

2026-04-27T12:39:07+03:00 ERR internal/upstreams/blocks/block_processor.go:133 > couldn't detect finalized block of upstream official-fantom error="-32602: invalid argument 0: hex string without 0x prefix" pid=526635
2026-04-27T12:39:07+03:00 ERR internal/upstreams/blocks/block_processor.go:133 > couldn't detect finalized block of upstream official-immutable error="-32000: finalized block not found" pid=526635

And there is no upstream to serve the requests.

By the way, the public and our private dRPC urls don't work for either version.