Assigning a With statement to one of two classes depending on a toggle, issues assigning New Object to be the same as another

I'm currently a bit stuck with the "Object Variable or With block variable not set error".

Still fairly new to using With statements to simplify my code, I have two instances on my Class "ContractSelection" Both existing instances (previousContract & currentContract) are both by this time in the code called as public variables, and set with values. In this Sub I am attempting to submit one piece of information depending whether they are looking at the current selection or the previous (a toggle in the userform).
Frankly I'm not sure if contractToUpdate = currentContract is even a valid statement, but i'm finding it difficult to simply google.

(in a Public Variable module)

  Public currentContract As ContractSelection
  Public previousContract As ContractSelection

(in Userform module)

Private Sub UserForm_Initialize()
  Set currentContract = New ContractSelection
  Set previousContract = New ContractSelection
End Sub

Values are set in general Subs like this

Sub setThePreviousContractAsTheCurrent()
   currentContract.DistrictNumber = previousContract.DistrictNumber
   currentContract.ContractName = previousContract.ContractName
   currentContract.RegionName = previousContract.RegionName
'...
End Sub

(In a Main Sub module) This Sub is where the issue is.

Sub submitNewCode()
  Dim contractToUpdate As ContractSelection, response As Integer
  Set contractToUpdate = New ContractSelection
  If CDBENC_Form.chkbx_PreviousSearch.value = False Then
     'vba stating the issue is here
     contractToUpdate = currentContract
  Else
     contractToUpdate = previousContract
  End If
  With contractToUpdate
   If .CodeOfContract <> "" Then
     If isSimilarByOne(.CodeOfContract, CDBENC_Form.txt_Code.value) = False Then
       dataSheet.Cells(.TheRowIWasFoundIn, dataMappedColumns.CodeColumnNum).value = CDBENC_Form.txt_Code.value
     Else
        response = MsgBox("The new code is close to the original, is " & CDBENC_Form.txt_Code.value & " the intended new code?", vbYesNo + vbQuestion, "Confirm Action")
         If response = vbYes Then
            dataSheet.Cells(.TheRowIWasFoundIn, dataMappedColumns.CodeColumnNum).value = CDBENC_Form.txt_Code.value
         Else
            Exit Sub
         End If
     End If
   End If
  End With
End Sub

I've tried checking for to see if for some reason currentContract is showing as nothing

this returns the else

If currentContract Is Nothing Then
 MsgBox "Current Contract is nothing"
 Exit Function
Else
 MsgBox "Current Contract is not nothing"
End If

I've tried both

Dim contractToUpdate As ContractSelection
Dim contractToUpdate As New ContractSelection

also putting in the public variables as well

Public contractToUpdate As New ContractSelection

Any suggestions help, I feel as though I'm close to the idea but far from the solution.

VBA requires the use of Set when assigning a value to an object-typed variable.
So:

If CDBENC_Form.chkbx_PreviousSearch.value = False Then
    Set contractToUpdate = currentContract
Else
    Set contractToUpdate = previousContract
End If

If you're interested in why that's the case: https://stackoverflow.com/a/9924325/478884