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.
{
    LOCK(cs_desc_man);
    if (!m_map_crypted_keys.empty()) {
        return false;
    }
    for (const KeyMap::value_type& key_in : m_map_keys)
    {
        const CKey &key = key_in.second;
        CPubKey pubkey = key.GetPubKey();
        CKeyingMaterial secret(key.begin(), key.end());
        std::vector<unsigned char> crypted_secret;
        if (!EncryptSecret(master_key, secret, pubkey.GetHash(), crypted_secret)) {
            return false;
        }
        m_map_crypted_keys[pubkey.GetID()] = make_pair(pubkey, crypted_secret);
        batch->WriteCryptedDescriptorKey(GetID(), pubkey, crypted_secret);
    }
    m_map_keys.clear();
    return true;
}
bool DescriptorScriptPubKeyMan::GetReservedDestination(const OutputType type, bool internal, CTxDestination& address, int64_t& index, CKeyPool& keypool)
{
    LOCK(cs_desc_man);
    std::string error;
    bool result = GetNewDestination(type, address, error);
    index = m_wallet_descriptor.next_index - 1;
    return result;
}
void DescriptorScriptPubKeyMan::ReturnDestination(int64_t index, bool internal, const CTxDestination& addr)