Ocasional missing `Paren beacon block root` missing

[emlautarom1]

Description
Occasionally, in OP-Stack based chains like Worldchain we get an error to process blocks with the message "Parent beacon block root must be set"

Steps to Reproduce

1. Run an OP-Stack compatible chain like Worlchain Mainnet using the official op-node alongside it.
2. Let Nethermind sync
3. Wait until a engine_newPayloadV4 request fails.

Actual behavior
Nethermind rejects the JSON-RPC request with the error Parent beacon block root must be set

Expected behavior
Nethermind should correctly process the request, iff op-node is sending valid requests.

Desktop:

• Operating System: Linux
• Version: Nethermind master (
• Installation Method: From source
• Consensus Client: op-node 1.16.3

Additional context
This issue has been reported a couple of times both internally and by users. We've had a hard time reproducing it.

Logs
Some logs from different scenarios:

Case 1 (Nethermind logs):

08 Dec 14:50:36 | Received ForkChoice: 22759715 (0x008067...daa54a), Safe: 22759715 (0x008067...daa54a), Finalized: 22759715 (0x008067...daa54a) 
08 Dec 14:50:36 | Payload for block 22759716 with same parameters has already started. PayloadId: 0x13aa21e19b39829c 
08 Dec 14:50:36 | GetPayloadV4 result: 22759716 (0x4a00e9...c51ae8). 
08 Dec 14:50:36 | Parent beacon block root must be set 
08 Dec 14:50:36 | Error response handling JsonRpc Id:338 Method:engine_newPayloadV4 | Code: -32602 Message: Parent beacon block root must be set

Case 2 (op-node logs):

Dec 11 08:51:35 server op-node[146876]: t=2025-12-11T08:51:35+0000 lvl=warn msg="failed p2p sync request" peer=16Uiu2HAmJdsiztYXHtHQYivC7URmvbg9cXnuGsYfSutCoSjnF6H3 num=39325203 err="failed to open stream: failed to negotiate protocol: protocols not supported: [/opstack/req/payload_by_number/8453/0]"
Dec 11 08:51:35 server op-node[146876]: t=2025-12-11T08:51:35+0000 lvl=warn msg="failed p2p sync request" peer=16Uiu2HAm2LCHJgBQCEuSoc5W8ApF1DoitnsQWyAMmBUW9a3GiZhw num=39325201 err="peer failed to serve request with code 1: not found"
Dec 11 08:51:35 server op-node[146876]: t=2025-12-11T08:51:35+0000 lvl=warn msg="cancelling p2p sync range request" peer=16Uiu2HAm2LCHJgBQCEuSoc5W8ApF1DoitnsQWyAMmBUW9a3GiZhw rangeReqId=427
Dec 11 08:51:36 server op-node[146876]: t=2025-12-11T08:51:36+0000 lvl=info msg="processing L2 range request" target=39321722 end=0xb3d3e01f5a0b2bcabedc7f372cecec08183201cc6f3adbfc163e9e2bd70178dc:39325204 rangeReqId=428
Dec 11 08:51:36 server op-node[146876]: t=2025-12-11T08:51:36+0000 lvl=info msg="no peers ready to handle block requests for more P2P requests for L2 block history" target=39321722 end=0xb3d3e01f5a0b2bcabedc7f372cecec08183201cc6f3adbfc163e9e2bd70178dc:39325204 current=39325074
Dec 11 08:51:38 server op-node[146876]: t=2025-12-11T08:51:38+0000 lvl=error msg="Payload execution failed" block_hash=0x28cd3ea49c268c7532ad538931875a903d359343fcf18ed48ae4d166574992a5 err="Parent beacon block root must be set"
Dec 11 08:51:38 server op-node[146876]: t=2025-12-11T08:51:38+0000 lvl=warn msg="Engine temporary error" err="failed to insert execution payload: failed to execute payload: Parent beacon block root must be set"

[flcl42]

By any chance we can reproduce it on a machine with snooper or request logging enabled?