Excel VBA Communicating with Jira using Isolated Site Minder cookies using REST - excel

Question

I have inherited an Excel Tracker sheet and the code originally was created by someone else who has since left the company.
We have an Excel VBA Tracker sheet which communicates with Jira and used to work fetching projects and issues without any issues until our company changed from site minder for cookies to "Isolated Site Minder" for more secure cookies, since the change over to the isolated site minder cookie authentication our Excel tracker sheet will fetch the project key from Jira without any problem but it brings the same list of 50 issues no matter which project we are querying Jira for and no matter how we change the code it wont see the issue "Key" and filter and fetch the correct issues for the project. I'm not brilliant as Excel VBA but I do understand and can follow what the code is doing and make small adjustments, but I have now inherited this tracker sheet and am not very good at the Jira code and communicating with each other
the code is as follows:
Public Function httpGet (ByVal url as String) As String()
Dim resultArray(2) as String 
Dim PostData as String
url = baseurl + url
Dim smiwhr As New SMIsolatedWinHttpRequest
With CreateObject("WinHTTP.WinHTTPrequest.5.1")
.Option(WinRequestOption_EnableRedirects) = True 
.Option(WinRequestOption_EnableHttpsToHttpRedirects) = True
smiwhr.NewRequest "GET", url
smiwhr.Send PostData
.Open "GET", url, False
.SetRequestHeader "Content-Type", "Application/json"
.SetRequestHeader "Accept", "application/json"
.SetRequestHeader "Cookie", sCookie
.Send
resultArray(0) = Status
resultArray(1) = .ResponseText
End With
httpGet = resultArray
End Function  
There is a function that gets the requests which has the code:
Public Function getRequestByPaging(ByVal projectKey as String, ByVal StartIndex as Integer, Optional maxResults As Integer, Optional fields As String) As Object
Dim resultArray() As String
Dim api as String
Dim jql As String
Dim PostData As String
api = "rest/api/2/search"
jql = "project=" & projectKey & " and issuetype!=\""Project\"" ORDER By Key ASC "
PostData = "{"
PostData = PostData + toJson ("jql", jql) + ","
PostData = PostData + toJson("StartAt", StartIndex) + ","
If maxResults <> "" Then
PostData = PostData + toArray("field", fields) + ","
End If
PostData = Mid(PostData, 1, Len(PostData) - 1)
PostData = Post + "}"
End Function  
The jql part does pick up the project key, it is when it sends the details of the project through to the Json that it returns the wrong issue key 
The Json function is as follows:
Public Function toJson (byVal As String, ByVal value As String) As String
If value = "" Then
toJson = """" + key + """ : null"
Else
toJson = """" + key + """ : """ + value + """"
End If
End Function
Any help would be very much appreciated

Answer 1

While editing your original question and adding syntax highlighting to it (otherwise your code cannot be read), I've noticed that the syntax in the function in question is probably wrong:
You had it:
If value = "" Then
toJson = """ + key + """ : null"
' ^^^ missing "
Else
toJson = """" + key + """ : """ + value """"
' ^ missing +
End If
It should be this way:
If value = "" Then
toJson = """" + key + """ : null"
Else
toJson = """" + key + """ : """ + value + """"
End If