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.
{
    return BerkeleyBatch::Recover(wallet_path, callbackDataIn, recoverKVcallback, out_backup_filename);
}
bool WalletBatch::Recover(const fs::path& wallet_path, std::string& out_backup_filename)
{
    
    
    return WalletBatch::Recover(wallet_path, nullptr, nullptr, out_backup_filename);
}
bool WalletBatch::RecoverKeysOnlyFilter(void *callbackData, CDataStream ssKey, CDataStream ssValue)