EIP-712 has a wallet refuse typed data whose domain chainId is not the active chain, because the signature is valid on the chain it names. The sign screen now shows such a request with the reason on its error line and Sign disabled, the same way it refuses a mismatched primary type. The background checks again when the signature comes back, against the network active then, and answers the site with that refusal instead of the signature. A chain id is read as ethers signs it, so 1, "1" and "0x1" are one chain. Typed data with no chainId signs as before. Model: opus-5-5