The total transaction count (for progress estimation) is counted as the known count at the last checkpoint, plus an estimated number per day.

The last checkpoint is now 996 days ago, and its estimated 60000 transactions per day leads to a total estimate of 96M transactions, while the real number is around 183M.

Fix this by updating the count, timestamp, and rate of transactions... with or without adding a new checkpoint.
{
    if (request.fHelp || request.params.size() != 0)
        throw runtime_error(
            "getmempoolinfo\n"
            "\nReturns details on the active state of the TX memory pool.\n"
            "\nResult:\n"
            "{\n"
            "  \"size\": xxxxx,               (numeric) Current tx count\n"
            "  \"bytes\": xxxxx,              (numeric) Sum of all tx sizes\n"
            "  \"usage\": xxxxx,              (numeric) Total memory usage for the mempool\n"
            "  \"maxmempool\": xxxxx,         (numeric) Maximum memory usage for the mempool\n"
            "  \"mempoolminfee\": xxxxx       (numeric) Minimum fee for tx to be accepted\n"
            "}\n"
            "\nExamples:\n"
            + HelpExampleCli("getmempoolinfo", "")
            + HelpExampleRpc("getmempoolinfo", "")
        );
    return mempoolInfoToJSON();
}
UniValue preciousblock(const JSONRPCRequest& request)