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.
{
protected:
    /**
     * Every received block is assigned a unique and increasing identifier, so we
     * know which one to give priority in case of a fork.
     */
    
    int32_t nBlockSequenceId GUARDED_BY(::cs_main) = 1;
    
    int32_t nBlockReverseSequenceId = -1;
    
    arith_uint256 nLastPreciousChainwork = 0;
    /**
     * The ChainState Mutex
     * A lock that must be held when modifying this ChainState - held in ActivateBestChain() and
     * InvalidateBlock()
     */
    Mutex m_chainstate_mutex;
    /**
     * Whether this chainstate is undergoing initial block download.
     *
     * Mutable because we need to be able to mark IsInitialBlockDownload()
     * const, which latches this for caching purposes.
     */
    mutable std::atomic<bool> m_cached_finished_ibd{false};
    
    
    CTxMemPool* m_mempool;
    
    std::unique_ptr<CoinsViews> m_coins_views;