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.
{
private:
    bool m_could_reserve{false};
public:
    explicit BlockFiltersScanReserver() = default;
    bool reserve() {
        CHECK_NONFATAL(!m_could_reserve);
        if (g_scanfilter_in_progress.exchange(true)) {
            return false;
        }
        m_could_reserve = true;
        return true;
    }
    ~BlockFiltersScanReserver() {
        if (m_could_reserve) {
            g_scanfilter_in_progress = false;
        }
    }
};
static RPCHelpMan scanblocks()