Internet Explorer object doesn't have Document child

I'm trying to get my hands on filling in a form with PowerShell. So I am simply trying to do this:

$ieObject = New-Object -ComObject 'InternetExplorer.Application';
$ieObject.Visible = $true;;
$ieObject.Navigate('https://www.randomizer.org/');
$currentDocument = $ieObject.Document;
$inputbox = $currentDocument.getElementByID('randSets');
$inputbox.value = "My Value"; 

However this gives me the error

You cannot call a method on a null-valued expression.
At line:5 char:1
+ $inputbox = $currentDocument.getElementByID("randSets");

I don't exactly know why but my ieObject doesn't have all the properties (I only have 9 when I'm supposed to have around 50)and methods it should have. When I use Get-Member I can't see Document in there so is it normal or am I doing something really wrong?

PS C:\Users\n> $ieObject | Get-Member

   TypeName: System.__ComObject

Name                      MemberType Definition                                            
----                      ---------- ----------                                            
CreateObjRef              Method     System.Runtime.Remoting.ObjRef CreateObjRef(type re...
Equals                    Method     bool Equals(System.Object obj)                        
GetHashCode               Method     int GetHashCode()                                     
GetLifetimeService        Method     System.Object GetLifetimeService()                    
GetType                   Method     type GetType()                                        
InitializeLifetimeService Method     System.Object InitializeLifetimeService()             
ToString                  Method     string ToString()                                     

Thank you in advance!

I am using:

• Windows 10 Enterprise (so I'm thinking maybe my company blocked some features, I will check with my IT department)
• Powershell version is 5.1
• Internet explorer version 11.885

EDIT: as suggested in the comment I tried to use VBA to do the same thing as my powershell script and I got the same error on the Document object Method 'Document' of object 'IWebBrowser2' failed'. This means I can't access properly my Internet Explorer application. In this case I think I should wait for the final answer of my IT department and then add more to this.

So I have access to the object and every property of it until I use Navigate. Then I get errors even for Get-Member like:

Get-Member : The following exception occurred while retrieving the string representation 
for property "Application" : "The RPC server is unavailable. (Exception from HRESULT: 
0x800706BA)"

What looks like is happening is the page has not loaded by the time you are calling $currentDocument = $ieObject.Document; causing $currentDocument to be $null.

You should be able to fix it by using .Busy

$ieObject = New-Object -ComObject 'InternetExplorer.Application'
$ieObject.Visible = $true
$ieObject.Navigate('https://www.randomizer.org/');
do{
   Start-Sleep -Milliseconds 10
}while($ieObject.Busy)
$currentDocument = $ieObject.Document
$inputbox = $currentDocument.getElementByID('randSets')