Occasional Missing Transaction Hashes in eth_getBlockByNumber

[emkjp]

Description
When using Nethermind, the eth_getBlockByNumber RPC occasionally returns a response where the transaction hash is missing.

Steps to Reproduce

JSON RPC call:

{"jsonrpc":"2.0","method":"eth_getBlockByNumber","params":["0x5c638c",true],"id":"0x400"}

Actual behavior
Response (with missing transaction hashes):

{
    "jsonrpc": "2.0",
    "result": {
        "author": "0xe276bc378a527a8792b353cdca5b5e53263dfb9e",
        ...
        "transactions": [
            {
                "nonce": "0x4a41e",
                "blockHash":
"0x29da6af53410c0b21eb89eb36a5ac167de77fc0dde0a89b04f3cecc11f954ce5",
                ...
            },
            {
                "nonce": "0x181",
                "blockHash":
"0x29da6af53410c0b21eb89eb36a5ac167de77fc0dde0a89b04f3cecc11f954ce5",
                ...
            },
        ...

Expected behavior

{
    "jsonrpc": "2.0",
    "result": {
        "author": "0xe276bc378a527a8792b353cdca5b5e53263dfb9e",
        ...
        "transactions": [
            {
                "hash": "0x916f03c07272f43edbc76eae947c02ca0e25d3866e4531e282235ef593ae5aaa",
                "nonce": "0x4a41e",
                "blockHash":
"0x29da6af53410c0b21eb89eb36a5ac167de77fc0dde0a89b04f3cecc11f954ce5",
                ...
            },
            {
                "hash": "0x40d2b40304c3cf50896fa174a92cd5d2d7eee9fdf02c09bb1f0428f76772827c",
                "nonce": "0x181",
                "blockHash":
"0x29da6af53410c0b21eb89eb36a5ac167de77fc0dde0a89b04f3cecc11f954ce5",
                ...
            },
        ...

Desktop (please complete the following information):

• Operating System: Ubuntu 20.04 LTC
• Version: 1.28.0
• Installation Method: PPA
• Consensus Client: lighthouse v5.3.0

Additional context

• In very rare cases, only for specific blocks, a response with an empty hash will always be returned.
• This issue started occurring after upgrading from Nethermind 1.20.3 to 1.25.4 and has also been observed in version 1.28.0.
• The issue happens on both mainnet and Sepolia networks.
• It is rare, occurring around 1-3 times per month.
• Restarting Nethermind resolves the issue, and the transaction hashes appear correctly in the response after the restart.