I've seen a lot of errors in Hive since we changed to use snap sync by default:

unexpected status on forkchoice updated to genesis: payload_status=PayloadStatus(status=<PayloadStatusEnum.SYNCING: 'SYNCING'>, latest_valid_hash=None, validation_error=None) payload_id=None

The tests starts by calling fork choice updated to the genesis block (block 0). By definition, you can't sync to the genesis block, so we should not return syncing, but we should return valid.

Handling the case where we call FCU to the genesis block would solve the issue. But going one step further, if we get a FCU call to any block which we have the state for, we should not return syncing, since we are already synced to that block, we just have to set it as head.