the command "bitcoin-cli getblockstats 0000000000000000000c61ff8f761ce509fc8901d3c22d61fec89637042ea2ba" does not work.

It displays "error: Error parsing JSON:0000000000000000000c61ff8f761ce509fc8901d3c22d61fec89637042ea2ba"

but it should display the block stats like the documentation says.

also bitcoin-cli getblockstats 0 does not work. block number must be at least 1 to work. But blocks start at 0.

tested with 0.20.1 on freebsd, another user on IRC acknowledged the problem.
ChainstateManager& chainman = EnsureAnyChainman(request.context);
    {
        LOCK(cs_main);
        pblockindex = chainman.m_blockman.LookupBlockIndex(hash);
        tip = chainman.ActiveChain().Tip();
        if (!pblockindex) {
            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
        }
        block = GetBlockChecked(chainman.m_blockman, pblockindex);
    }
    if (verbosity <= 0)
    {
        CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION | RPCSerializationFlags());
        ssBlock << block;
        std::string strHex = HexStr(ssBlock);
        return strHex;
    }
    TxVerbosity tx_verbosity;
    if (verbosity == 1) {
        tx_verbosity = TxVerbosity::SHOW_TXID;
    } else if (verbosity == 2) {
        tx_verbosity = TxVerbosity::SHOW_DETAILS;
    } else {
        tx_verbosity = TxVerbosity::SHOW_DETAILS_AND_PREVOUT;
    }
    return blockToJSON(chainman.m_blockman, block, tip, pblockindex, tx_verbosity);
},
    };
}
static RPCHelpMan pruneblockchain()