Alchemy Account Kit: eth_getUserOperationReceipt returns null and tx ultimately fails on Optimism Sepolia

[syuhei176]

Hi Alchemy team,

I’m integrating Account Kit and seeing an issue on Optimism Sepolia since last week, where eth_getUserOperationReceipt consistently returns null, and the transaction ultimately fails.

Summary
• Chain: Optimism Sepolia (chainId: 11155420)
• Symptom: eth_getUserOperationReceipt keeps returning null for the userOpHash, even after waiting beyond typical inclusion times; the user operation never finalizes into a successful L1/L2 tx.
• Result: End-to-end send fails from the client perspective.

@account-kit/core: 4.66.1
@account-kit/react: 4.66.1