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);
    return m_wallet_descriptor.creation_time;
}
std::unique_ptr<FlatSigningProvider> DescriptorScriptPubKeyMan::GetSigningProvider(const CScript& script, bool include_private) const
{
    LOCK(cs_desc_man);
    
    auto it = m_map_script_pub_keys.find(script);
    if (it == m_map_script_pub_keys.end()) {
        return nullptr;
    }
    int32_t index = it->second;
    return GetSigningProvider(index, include_private);
}
std::unique_ptr<FlatSigningProvider> DescriptorScriptPubKeyMan::GetSigningProvider(const CPubKey& pubkey) const
{
    LOCK(cs_desc_man);
    
    auto it = m_map_pubkeys.find(pubkey);
    if (it == m_map_pubkeys.end()) {
        return nullptr;
    }
    int32_t index = it->second;
    
    return GetSigningProvider(index, true);
}
std::unique_ptr<FlatSigningProvider> DescriptorScriptPubKeyMan::GetSigningProvider(int32_t index, bool include_private) const