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.
{
    for (unsigned int i = 0; i < psbtx.tx->vin.size(); ++i) {
        const CTxIn& txin = psbtx.tx->vin[i];
        PSBTInput& input = psbtx.inputs.at(i);
        if (PSBTInputSigned(input)) {
            continue;
        }
        
        if (!input.IsSane()) {
            return TransactionError::INVALID_PSBT;
        }
        
        if (sign && input.sighash_type > 0 && input.sighash_type != sighash_type) {
            return TransactionError::SIGHASH_MISMATCH;
        }
        
        CScript script;
        if (!input.witness_utxo.IsNull()) {
            script = input.witness_utxo.scriptPubKey;
        } else if (input.non_witness_utxo) {
            if (txin.prevout.n >= input.non_witness_utxo->vout.size()) {
                return TransactionError::MISSING_INPUTS;
            }
            script = input.non_witness_utxo->vout[txin.prevout.n].scriptPubKey;
        } else {
            
            continue;
        }