eth_estimateGas fails with: "invalid argument 0: json: cannot unmarshal non-string into Go struct field TransactionArgs.chainId of type *hexutil.Big"

Bugs
1

In the past, we could pass a numerical chainId value into web3.eth.estimateGas (which calls eth_estimateGas) and get a valid response.

It seems that now, it fails with:
invalid argument 0: json: cannot unmarshal non-string into Go struct field TransactionArgs.chainId of type *hexutil.Big

This breaks our service.
Was the API changed? Can it accept chainId again?
Or maybe ignore it altogether as the chain-id is determined by the Infura host anyway?

2

From the error message, it looks like TransactionArgs.chainId needs to be a bigint as a hex string with 0x prefix. That should be a relatively easy fix within your code. Otherwise, you can try to remove the chainId.