When running walletpassphrase on a large wallet.dat (ie about 300,000 segwit P2SH addresses) the command sometimes takes a very long time, and if command is run multiple times at once (while running slow) it causes bitcoin core to freeze (stops syncing and requires kill -9 to stop/restart)

During the locked up walletpassphrase commands being run the following messages start to appear in the debug.log:

`018-01-24 01:01:04 socket sending timeout: 1201s`

Note that this problem is intermittent, so sometimes the command runs instantly, other times it takes a few minutes, and other times it completely freezes the node.
ssKey >> pubkey;
            if (!pubkey.IsValid())
            {
                strErr = "Error reading wallet database: CPubKey corrupt";
                return false;
            }
            std::vector<unsigned char> privkey;
            ssValue >> privkey;
            wss.nCKeys++;
            wss.m_descriptor_crypt_keys.insert(std::make_pair(std::make_pair(desc_id, pubkey.GetID()), std::make_pair(pubkey, privkey)));
            wss.fIsEncrypted = true;
        } else if (strType != DBKeys::BESTBLOCK && strType != DBKeys::BESTBLOCK_NOMERKLE &&
                   strType != DBKeys::MINVERSION && strType != DBKeys::ACENTRY &&
                   strType != DBKeys::VERSION && strType != DBKeys::SETTINGS) {
            wss.m_unknown_records++;
        }
    } catch (const std::exception& e) {
        if (strErr.empty()) {
            strErr = e.what();
        }
        return false;
    } catch (...) {
        if (strErr.empty()) {
            strErr = "Caught unknown exception in ReadKeyValue";
        }
        return false;
    }
    return true;
}
bool WalletBatch::IsKeyType(const std::string& strType)