VBScript GetObject() not working if called from C# WPF application

I have the following VBScript code in MyScript.vbs:

Dim myApp    
Set myApp = GetObject(,"ViewDraw.Application")

I call it from a PowerShell command line, like so:

cscript MyScript.vbs //I

This works as expected; myApp is set to the process I'm looking for and I'm able to interact with it.

Here's some C# code that attempts to do the same thing:

var script = new Process();
script.StartInfo.FileName = "cscript";
script.StartInfo.Arguments = @"<MyWorkingFolder>\MyScript.vbs //I";

script.StartInfo.CreateNoWindow = true;
script.StartInfo.RedirectStandardOutput = true;
script.StartInfo.UseShellExecute = false;
script.Start();

//Read anything sent out by program
string output = script.StandardOutput.ReadToEnd();

script.WaitForExit();

VBScriptResult result = new VBScriptResult();
result.returnCode = script.ExitCode;
result.stdOut = output;
return result;

When I execute the C# code, the VBScript fails on the GetObject() call. There have been similar SO questions, and I've tried their suggestions. One suggestion was to explicitly call either the 32bit or 64bit version of cscript. Neither worked, however.

This hasn't always been an issue. The code is a couple of years old now and has worked in the past. It's possible that an update to Visual Studio 2017 somehow caused this problem. I'm currently running version 15.3.5.

I've been stuck on this issue for a week now, so any help is greatly appreciated!