🐞 Bug Report

Description

go-eth2-client assumes success of a call as soon as 1 BN returns successful response. This may cause issues in the following scenario:

An operator has 2 BNs wired up.
On the response of POST /eth/v1/validator/prepare_beacon_proposer BN A silently errored while BN B returned a success.
Then in a subsequent request to create a block, the first to respond was BN A. BN A doesn't have default fee recipient address set as a flag, so it defaults to the zero address. This results in loosing the extra rewards of the block proposal.

Has this worked before in a previous version?

No.